You described the differences pretty well.
In Destiny 1, shaders were normal items - they were not consumable. There was only one shader slot, and it applied to all your armor (weapons were not affected (related, most exotic weapons had one or two ornaments that worked similar to shaders, but were consumable)). You could change the shader at will, and the shader would not be destroyed. Later on in Destiny 1's development they added a shader kiosk where you could get a new copy of any shader you have ever found which would allow you to effectively use the same shader across all your characters.
In Destiny 2, shaders are now applied per item and can be applied to weapons, sparrows, ships, and ghosts in addition to armor. Shaders are also consumable - once you've applied a shader, you can't use it again. If you replace it with a different shader, the first shader is gone. When a shader drops, you typically get a few copies of it (I've gotten 3 at once, not sure if that is guaranteed).
The main issue some members of the community have with the new system is that in addition to being consumable (which means you tend to think about applying a shader, since you can't use it again), is that you can buy them with real money via the Eververse store. The conspiracy theory is that shaders were made consumable so that Bungie would make more money on microtransactions.
The biggest difference is that Region Chests don't respawn. Once you've opened the gold chest, you can't open it again. Ever. On any other character. They contain 3 faction regional faction tokens, 1000 glimmer, and occasionally a Rare or Legendary Engram.
The standard caches respawn frequently, and generally contain a (1) regional faction token, some glimmer, roughly 250, I believe, and the chance of a Rare or Legendary Engram.
Best Answer
There are 5 regional chests on Mercury. They can be picked up once per character. Opening all 5 gets you an emblem, 5 Mercury tokens, and 2-3 legendary items.
Locations for all 5 chests:
Chest 1
In the Lighthouse, there are 5 books with glowing crosses on them around the area. These have to be pressed in the correct order and can be acted upon by pressing your action button (you will be prompted)
After this, you can head to the trenched area to the right of Brother Vance, where a conflux will appear. Use your action button on it, and it will open up a little doorway in the opposite trenches that contains the first chest.
Chest 2
At the area where you spawn in when you travel to Mercury, turn around, and take the path that leads to the back of the Lighthouse(not inside, but in the actual patrol area). There will be a Colossus guarding the chest. You can kill him and get the chest or get the chest and not kill him. But those stun rockets are too annoying and overpowered to move past.
Chest 3
To the right of the entrance to the Infinite forest, there is a bunch of Vex plating on the wall that is scale able. It's pretty hard, but when you get up far enough you can see a ledge up to the left you can try to jump up and grab it. It's a little tough. Fair warning.
Chest 4 and 5
Chest four and five can be activated in the same way, but require you to make the public event heroic, and unless you do something like stall on one side of the event, you may have to wait for the next event. They are located on both of the islands you can get boosted to.
Whatever island you get boosted to first is the only island you can activate heroic on. Do the normal steps you can do to activate heroic ( First video that came up on google) and when you reach the top, you can find the chest up there.
Keep in mind whoever puts the arc charges in last on their side is which island you get launched to, so choose your strategy carefully!! For those who didn't see the beginning, you can get an wmblem, legendary loot, and Mercury coins for getting the five chests.
(Taken from https://www.reddit.com/r/LowSodiumDestiny/comments/7ijroc/mercury_regional_chest_guide/).