Hi there!

Does anybody know if SKSE installed has any affect on the general performance of the game, positive oder negative? Should it be uninstalled when not used by mods?

Thanks for answers!

To my knowledge it does nothing if no mods are calling it's functions, rather it's a library of extra functions that can be used by mods that need what the Vanilla library cant offer. Any impact on performance would result from mods using SKSE.

SKSE is a script extender. As far as I know, it doesn't affect the game's performance -at least not by itself.

You don't have to uninstall it and honestly, I can't think of a reason why you would want to do so, especially with http://skyrim.nexusmods.com/mods/3863, being around

You can ask in the http://www.gamesas.com/topic/1429397-wipz-skyrim-script-extender-skse/ but I'm pretty sure it doesn't affect performance at all.