There is MUCH that can be done simply reducing all crpg textures (and native texs used by crpg) by half resolution. Why this isn't done I don't know since the visual difference is often so unnoticeable it's not even worth mention. Large textures are fine for native since there isn't too much gear and it isn't all being loaded at once but for crpg which has many additional items it's just a huge waste of resources using such large textures IMO.
I know, but no matter what, more diversity in the available content means more to load. Or at least not less.
Better yet, people could stop using ancient PC hardware that barely meets the minimum requirements and get something a bit better, then they wont get any lag at all.
The kind of problems created by more textures etc. in this game is heavily linked to the amount and speed of the RAM you have, and what type of OS you use (32 or 64 bits). My previous pc had a decent 4Gb and was booting on XP 32 (so roughly 3,1Gb of RAM were used), yet I had "alternating frames" freezes very often.