Typically the rule is not to uninstall mods that your savegame depends on, but mods that it doesn't depend on are safe. For instance, let's say you use a custom head or face mod. If you remove that mod, the game will likely crash on load b/c it will try to load an asset that doesn't exist. Same with classes, if you try to load a game where you're a custom class, but you've removed the mod that adds that class, it's likely crash o'clock. Armors and Spells are likely more lenient. If you remove a spell mod and a character has that spell, then they just won't have it any more. It's a little tricky, but try it and eventually you'll get a feel for what can and can't be uninstalled. But if I had to give you two pieces of advice: 1. Add mods *slowly.* Add one, maaaybe two mods that you really want to play with, then play with them for a couple of hours to be sure it's stable before adding more. 2. Make backups: Every time I add a mod, I make a (non-quick) save titled "last before {mod name}" If the mod screws stuff up, I know exactly where I can go back to.