So if I remember correctly, fallout had main quest scaling but the rest of the world was set to a specific level?
Main difference is that we get dungeons with different difficulty, levels: some is 1-8, other is perhaps 10-20 or 30 to 50, then you enter a dungeon it get locked to your level or as close as you get, if you enter a level 10-20 dungeon at level 10 it will be level 10 even if you return at level 21, but if you first time enter at level 25 it will be max who is 20.
Dragons can apear everywhere and will probably be leveled to your level, however if you run into them in dungeons I would expect them the be at the dungeons level.
Noting is said about respawning as far as I know.