My car alarm will sound sporadically and turn off on it's own. Is it possible just to disable the alarm?

This normally happens when the siren battery starts to go bad.

Here is a great write up on how to replace it; it should be the same for your year I believe. But some people suggest not replacing with those batteries listed as some have had problems.
http://home.datacomm.ch/saeuberli/fi..._batteries.pdf
Some suggest these batteries instead, you need the axial lead (CR123A)--->>http://powerstream.com/LiPMnO2.htm

Also, when you pull the key out of the car, push and hold down the "Night Panel" button and I guess you can change the settings. Just what I read though, and I think it needs to be done every time you pull out the key.

Thank you, can I just bypass the alarm system and not have it in use?

I believe you have to have a TechII to do that, so you'll have to take it to the dealer. But I'm not entirely sure it's possible.