For one thing, no difference was made because you installed the 1.3.2 version. Did you install it to modpack.jar? FPS drops are normal, mods take up ram.
Well, I didn't know you didn't have a desktop with you because you made it sound like you had one. Try turning video settings down, or replacing the Optifine that is in Technic with standard.
The only issue here is that non-player entities don't load different dimensions on SSP. This might work when 1.3 comes out, but for now, to do things in the nether, you need to be in the nether.
Just be warned that perms are a pain in the ass. One YAML mistake means the server crashes. Reason behind the semi-rant: I lost my old server files, INCLUDING permissions.yml. Grrrr.