>>368215123
Memory in unity is handled in a virtualised fashion; it's passed to a garbage-collected memory pool when the asset is loaded, and then lower level it handles when the textures need to be in VRAM and when they're fine in RAM. Deactivated game objects get garbage collected in VRAM.
Blacklights used by DPS have a performance penalty as it's doing real time light calculations, but when they're off they aren't doing anything. 
High lightcount avatars are likely to be poorly optimised in general since lights stick avatars in very poor very quickly so they don't bother optimising anything.