Firstly, I am currently looking for feedback on the vBulletin importer and there have been reports that users do not get imported correctly, did your users get imported correctly?
eg. Migrating vBulletin 4.0.4 to bbPress 2.2.3 and bug tracking ticket #1991.
What version of vBulletin and bbPress are you using?
I personally don’t have access to vBulletin so I haven’t been able to test much of anything relating to vBulletin basically so helping out with your .htaccess would also be a bit of hit and miss.
Stack Exchange has some great examples of rewrites
This is one of my favourites even though it is not specific to any of your needs here it is a good example of mod_rewrite regex rules.
A couple of other resources to help along the way:
Hi Stephen. The bbpress built-in import tool didn’t work for me and paid the guys from gConverter.com to do it. They did a great job with the conversion and everything is working fine now.
Regarding the htaccess rules, i have no idea how to write them even after reading the resources you posted. So if there’s anyone here who can help, i would really appreciate it.
I posted my question on StackOverflow as well.
I have to find a solution fast because i’m currently losing a lot of SE traffic.
Thanks for the info on importing from vBulletin.
Hopefully someone can help out with some rewrite rules for you soon.