[pumkinut]

Have you tried possibly looking into using XBMCbuntu and installing all the things you have installed. There are linux versions of each. I'd either try that out, or find out where you memory's going. Have you even investigated that? It may not be XBMC that's eating memory, but something definitely has a memory leak.

I thought if you install xbmcbuntu that's all you got was xbmc.. Nothing else. I didn't know you could run other programs too

Even if it were just XBMC, it'd still need an operating system. Everything you currently have installed, except uTorrent, is actually a backend program that's access through a browser, so even without a window manager per se, it would still work, you would just access the other applications across your network with a web browser.