Here's a technique I've used. When I invite people to a game I tell them that the game we're playing is a homebrew system called "Valadil's Game" which is loosely based on D&D.
This does a couple things. Firstly, it scares off rules lawyers who want to play RAW. I figure those players aren't compatible with my games anyway and I'd rather just nip that in the bud. It also signals to the players that this isn't another kick down the door, slay the monster, loot the treasure D&D game. It removes that expectation and opens them up to something with more story.
If you want to get technical about it, this is just a restatement of Rule 0. But it works.
In the Fate Core rulebook, there's a section called the Veteran's Guide on p.294. That's a good place to start for differences, but it turns out it's even easier than that. On the G+ Fate Core community, someone compiled the rules changes from Fate Core to Dresden Files.
I thought this was rather light, but after playing, I can tell you that this distilled document is pretty much the complete list of changes, though one bit did throw me off. In the document, its stated that spin is no longer optional; it's a bit simpler than that. I suppose that the author was trying to define things so that people could see it using completely the DFRPG rules. That part is actually distilled down to the fact that there are four outcomes (which distills spin). There is also succeed with a cost, which definitely has opened up some avenues in my own experiences in Dresden Files.
There's also the simplified actions- those being Attack, Defend, Overcome, and Create an Advantage. A couple of things that were also left out from the Veteran's guide - the fact that aspects can be invoked in new ways: teamwork, to give another character +2 to roll vs. relevant opposition, and most importantly to me, to create or fortify an obstacle, i.e. give +2 to active opposition, or create opposition if it was not already there.
A couple of things that are left out which we had already started using, but others may not have. Zone borders are replaced by situational aspects. This is very important, and we had started to use those in any case in my game. What this lets you do is play without maps, and it's very helpful in other realms, as I found even defining zones when in the NeverNever to be a bit limiting. Supplemental actions and skill modifiers are removed- and we'd already done so.
There's also one rule from Fate Core that I did institute to help even more. I found that the focus on fewer aspects in Fate Core was definitely a good change, and after talking with my players, we were able to pare down our aspects. They didn't begrudge the change, and it didn't really limit them, but it does take conversation, as it does, on the surface, seem like you're losing something.
As far as whether it's worth it, in the end, I've made several other changes that fit together with Fate Core a lot more, so it was definitely worth it to me. In the Pros columns just in general, Fate Core is much clearer and definitely better written IMO. In the Cons column, there's a lot to Dresden Files that isn't really in Fate Core, so you're going to need two books for rules. But other than those two details, it really depends on what you're comfortable with. There's no inherent dissimilarities that would make it a no-go, and I think that was done on purpose. Even though Fate Core is said to be the ground zero of a generic Fate system, it really is iterative, and there aren't really any incompatibilities that I've found.
UPDATE: Looking at the additions in the question, there are some interesting ideas there. But other than a couple of things from the skills, I probably wouldn't use them. In the end, my particular flavor of Dresden Files has gone more narrative. If I don't need it for the narrative, I don't sweat it. Both the tweaks and the Evocation seem like they add a lot of complexity for its own sake, when Dresden Files is already complex enough. And they don't really add anything that the ballparking it from the rules of Fate Core and ignoring the rest do. For example, the rules about moving zones haven't really come into play a whole lot in my game- mostly because the whole zone thing has been one of the weakest parts to me. The situational aspects of the scene help a whole lot more with making zones narrative, and since adding them, my RCI (Red Court Infected) in my game has actually felt a lot faster as opposed to the movement through zones, and the others have actually not stumbled over the use of zones as much- it's just organic now.
There are some good ideas in there- I'd just try to look at the flip side of what you're giving up. Fate Core to a large extent is just more intuitive to me. And in taking that same philosophy in my translation and in my moderation, things have started going a lot faster since I've been integrating them, and we've made a lot more actual narrative progress.
Best Answer
This is hard work and probably a bad idea
This is not the answer you want to hear, I suspect, because you've offered a bounty for it. But, this is mostly a bad idea, for all the reasons you listed above dealing with mechanics.
RPG mechanics systems are tools-- they're designed to achieve certain effects and to support certain game worlds, and almost none of them are designed to be compatible with any other ones. Heck, even most of those game worlds are not compatible with the other ones: What obvious, or even plausible, translation exists between a D&D cleric and the Twilight 2000 game world?
Then realize that you have to do that at least six times (for your six desired games) and you have to do it faithfully enough that all the various characters and support gear from each system translates correctly.
There is no 'simplest,' here, this is an inherently complex task.
But if you absolutely must....
...Then at least use a tool designed for it. Do not fixate on translating everything into 5e. This is emphatically not what 5e was designed to do. At all.
There are a few RPGs that are at least deigned to emulate multiple genres, usually referred to as "generic" RPG systems. As it turns out, I have some limited experience in going to and from these generic systems. If you must do this, translate everything into that one chosen generic system and run with it.
One is GURPS, where I contributed an answer along these lines. This, at least, is sorta what GURPS is meant to do, although in my direct experience, it won't do it very well, and you will still need to do a lot of heavy lifting to convert all those systems. But it will be better than trying to use 5e.
There are other possibilities and I'm certainly not going to list them all, not least because I don't have experience with them all. I will list one more, though, for a particular purpose: Everway was not designed with genericity in mind, but it does seem particularly well suited to it. (I include that link not because it has details on how to adapt Everway, but only to demonstrate that I'm not the only person who thinks this.)
I have experience playing in an off-genre Everway game, and it works very well for what we want it to do-- well enough that in my copious free time, I am also adapting it for a Star Wars game.
The real reason I bring up Everway, though, is to drop one more observation and contrast on you: Some generic games (like GURPS) are detailed and rules heavy. Some (like Everway) are very rules light and abstract. If you go this route, I strongly encourage you to go toward the rules-light end of the spectrum. In my experience, it just works better because there's a lot less work to do.
Now, I realize that what I've just said is, "Don't do this. This won't work, and if it does it won't work well. If you really must do this, do this substantially different thing instead."
But that's the best honest advice that I can provide with well over three decades of gaming experience.