For Vision, Daylight and Bright Are The Same
For vision and hiding purposes, there are only three levels of light, as you mentioned. Bright, Shadowy, and Darkness.
"Bright" in this case means it's bright enough that there is no hindrance to vision at all. "Shadowy" grants concealment, and Darkness creates effective blindness if you can't mitigate it.
So yes, for these rules, a torch you're holding and the sun are the same thing, within the "bright light" range of the torch (20'). Outside of that range, the torch stops providing bright light. Get some distance on someone with a torch and you move into shadowy illumination against them instead. (If you have different vision modes than they do, you could actually have different conditions to see them then they have to see you, depending on the light.)
example:
If you're holding the torch, you're in bright light and can't Hide without Cover.
If someone else is holding the torch and you're 5' away from them, you're in bright light and can't Hide without Cover.
If someone else is holding the torch and you're 25' away from them, you're in shadowy illumination. That grants you Concealment, and you can Hide.
The same rules apply for any light source, you can use the Vision and Light table for the effective ranges of different light sources.
So what's Sunlight do?
The sun creates both bright light and bright sunlight. The difference is only in the case of monsters or effects that mention something related to that, like an Orc:
Orcs are dazzled in bright sunlight or within the radius of a daylight
spell.
A torch doesn't generate bright sunlight, so in this case it's different.
This Creates Lots of DM Interpretation
As you noticed, this gets confusing pretty fast when Shadowdancers get involved. Just what is "some sort of shadow", and where is it? Ask your DM. It's relative to the light, the position of the light source, the size of the thing casting the shadow, and the rules don't have anything to say on the matter whatsoever.
How big a shadow do you need to use it? Doesn't say. How much shadow is enough shadow to shadow jump? Doesn't say. How long is the shadow being cast by the enemy in front of me? Doesn't say. (This is probably why Pathfinder changed the wording on some of these abilities to be near "dim light" instead, which is more of a known rules thing than "some kind of shadow.")
As a DM dealing with a player who uses these abilities, it can get pretty confusing to try and sort out. It's actually easier in a dungeon with no light of its own, because if some player is carrying a light source, we can map it out on the board pretty easily relative to them and see where the shadowed areas would be (and which direction the player shadows are going, if you want to hide in the shadow of the Wild Shaped Druid).
But in an outside area at 5pm? Where are the shadows in that? It's a lot of work to sort out exactly how it all works, and it's often easier to come up with a simple rule of thumb and apply that rule of thumb consistently.
Hide
The one exception you mentioned is "how dim is dim enough?" In order to use Hide, you need concealment. Shadowy Illumination provides that. So you need to be in Shadowy Illumination, which is going to depend on what the area's light sources are (but most of those have a radius of providing light, and the table in the first link I provided has those distances).
You also need to be not being observed. If they're watching you, even with Shadowy Illumination, you can't use Hide. "Watching you" basically means they can see you at all, because in D&D vision is omnidirectional: characters are looking in every direction on every turn.
That's part of what makes Hide in Plain Sight so good (with HiPS, you can use Hide while being observed).
Yes, it is possible but...
The number of ways you can go about it is limited to somehow seeing through magical darkness like by getting Truesight.
Or by picking up 2 levels of Warlock for the Devil's Sight Eldritch Invocation, in order for you to see through magical darkness up to 120 feet.
Or by any means like the 6th-level Divination Spell True Seeing, or a Gem of Seeing (page 172 of the DMG) also does the trick, or you can homebrew a magic item that serves this purpose.
What is important is that you can see the area of magical darkness/dim light created, all others might still see it as magical darkness, that doesn't matter.
However, the bottom line is that both of these features were not meant to provide a mini-portal for the monk to Shadow Step through because Shadow Step, by its wording:
Shadow Step
At 6th level, you gain the ability to step from one shadow into another. When you are in an area of dim light or darkness, as a Bonus Action you can teleport up to 60 feet to an unoccupied space you can see that is also in dim light or darkness...
Emphasis on shadow here, we can see that the intent was for the Monk to step through shadows, not magical darkness. I know this sounds silly but if we look at the next emphasis, "you can see", it affirms this intent by limiting the area a Monk can step through to an area he can see. Hence, these two were not meant to be used in-tandem due to its incompatible properties. However, there are many uses for Darkness and Shadow Step alone in themselves. Darkness can be used to Blind enemies, causing them to have Disadvantage on Attack Rolls. One clever trick is also to use Darkness to cover a room's light source like a single torch, Darkness negates that source and engulfs the whole room in natural darkness, giving any creature with Darkvision advantage. Shadow Step can enable the Monk to avoid stepping into a brightly-lit portion of a room (and thereby avoid being seen) by teleporting to a dimly-lit portion.
Don't misunderstand me, stepping through magical darkness can be done but you'll have to work for it
Best Answer
The 1st-level Sor/Wiz spell ebon eyes [trans] (Spell Compendium 77) is a confusing mess, because, as written, it does allow the affected creature to see through natural and magical darkness. As the core rules place an otherwise high premium on the ability to see without a light source through natural darkness and even higher premium on the ability to see through magical darkness, it seems strange that a 1st-level spell should obviate both, but the spell ebon eyes does, and the spell does so apparently to the limit of the affected creature's normal vision.
"So ebon eyes is awesome?"
As written, yes. While there are many ways of gaining darkvision, gaining darkvision to the limits of normal sight is otherwise the sole the province of the obscure 4th-level Sor/Wiz spell superior darkvision [trans] (Unapproachable East 53). And while there are a handful of ways of gaining the ability to see through magical darkness, only the equally obscure 7th-level Sor/Wiz spell fiendish clarity [div] (Fiendish Codex I 94) allows seeing through magical darkness as if it were normal darkness, hence to the limit of the affected creature's darkvision (yet the spell itself only provides, among other effects, darkvision 60 ft.). For further comparison, the 3rd-level Fiendish Codex II spell devil's eye and the spell true seeing only allow seeing through normal and magical darkness out to, respectively, 30 ft. and 120 ft. Further, note that these spells are the best ways of almost duplicating the effects of the spell ebon eyes; domains, feats, and magic items are, objectively, worse at the task.
This makes the 1st-level spell ebon eyes the best see-in-the-dark spell printed for Dungeons and Dragons 3.5.
For a more conservative approach to seeing in the dark
It's true that the game overvalues the ability to see in the dark without a light source, and it's true that the game overvalues the ability to see in magical darkness. However, just because such abilities are overvalued doesn't change their values.
Thus a conservative DM may view the spell ebon eyes as, perhaps, a little unbalanced.1 For such a cautious DM, below are two options.
Consider using the original version of the spell ebon eyes...
When the spell appeared in the Dragon #322 article "Patterns of Shadows and Light: Same Coin, Different Sides" by Jason Nelson, it looked like this:
In other words, the Dragon magazine version is a low-level spell that grants the subject the ability to see normally only through magical darkness, to the limits of the affected creature's own vision. For example, in an area of magical darkness that's also naturally dark, a creature affected by the spell ebon eyes that lacks darkvision still can't see without a light source, but a creature possessing darkvision can see to the limits of its darkvision.
...Or just changing the first natural to unnatural
As written, the full Spell Compendium description of ebon eyes is, honestly, borderline gibberish, but change the first natural to unnatural and the spell's effect is a bit clearer:
Emphasis mine. A conservative DM could do worse than make this minor change.
1 Such a DM should, however, note that only the most unusual campaigns will be ruined by allowing such a low-level see-in-any-darkness spell. For example, in the core rules, even a low-level party can pay a 20th-level spellcaster 1,850 gp to cast on an object continual flame heightened to a 9th-level spell therefore eliminating most worries about magical darkness unless the object's specifically targeted by other effects.