Don't see the game needing more then 2GB even with texture mods, but yeah you could make the exe large address aware in order to access more than 2GB.
But anyways, the launcher overwrites the patch.
Wouldn't make any difference, the game only requires 512MB of RAM....making use of more cores would be interesting though...the game runs the same on my desktop with a SSD as it does on another PC with mechanical HD..not really any good way to increase loading times as chuk said.