Steven's problems were caused by an analog stick pattern. If he moved it in a certain pattern, it would freeze, and the only way to turn it back on was to remove the battery then reboot it. My PSP freezes occasionally too, so it may just be that fats have some processor glitches. The good news is, I have never heard of anything like this happening with a slim. The bad news is, they're expensive, especially when you've already bought a fat. :[ Hopefully the problems subside; I don't think it has to do with the firmware, but if it gets really bad, you might want to switch to an official firmware version to see if that helps.
Try asking on some PSP hacking forums to see if others have had similar problems and if it's fixable.
Don't worry about the Monster Hunter; I can just torrent it, and I deleted all my data on accident so I haven't really bothered to play much recently anyway. I don't expect you to replace that or pay me anything for the bass until you've gotten a steady job and you've gotten the other things that were stolen replaced.