Based on the problems you've listed, I assume you're using Windows. They've yet to make a truly stable windows port of the program, and at least the last time I looked, they basically wished Windows users luck and said they'd work on it when they had time -- it's very much not a priority for the software. I suppose it's still better than not being able to use it at all, though. If it's any consolation, many people (including some of the developers) are amazed that it runs on Windows at all.
As far as the fonts go, I suggest not leaving them all installed -- get a font manager and keep them in a central folder elsewhere.
Adobe Type Manager is good if you have a bit of cash to spend (it's about $70 as I recall), or else in the realm of free products,
The Font Thing works pretty well. Just leave the fonts that come with the operating system in, and install and uninstall others as you need them. Most graphics programs don't like large numbers of fonts, and as a general rule of thumb free programs like it even less.
As far as random closing goes, the best I can really suggest is save a lot, and send in a bug report. And, as was suggested, make sure you're using the most current version. In order to have any better guesses as to why it's doing that, I'd need to know more details -- what kind of computer you have, operating system version, processor and memory, other programs running at the same time, other things hooked up to the computer (I'd assume mouse, for example, but wacom tablets often cause problems with gimp), etc.