[Ntfu2]

Is it possible? Yes, make a couple backups of your database and download them all

Is it hard to do? No

Whats the chances of screwing it up? Great if you've never done it before/aren't familiar with the process. Slim if you've got a semi-firm grasp on basic administration operations

How to move it? Backup DB from dreamhost multiple times to prevent getting a corrupt one. If you have attachments stored in file system you'll need to back those up as well and download. Then simply reupload vBulletin files onto new host, Upload new database, and have them restore it. Repload attachments if neccassary

What if i want to keep my domain name as it is? You'll need to simply change the name server information where ever you registered it.

How to move the database? if small, use PhpMyAdmin and just do a couple basic web dumps of it.

Am i doing the right thing? [I am gettin lots of error msgs on Dreamhost - Mainly, 500 Server error/Site down] Probably, if you can't fix the errors and dreamhost isn't much help to you.