Static integration

[djdub]

A company website wants to provide support forums to it's customers, and also wants to control how certain types of customers view content. vBulletin appears to fit this bill with it's user groups.

What they would like to do, if it is possible, is to make the style of the entire website consistent.
I suppose I have two primary options. Make the non vB pages mimic the style of the vBulletin forums, or make the vBulletin forums mimic the style of the remainder of their website.
What I would like to inquire about is the latter.

So, perhaps I could setup stylized set of theme settings and template formats (particularly header and footer templates) in vBulletin to satisfy the customers need to have it represent the general style of their company.
What would be optimal, then, would be to then use vBulletin through out the remainder of their website so that I could use the company theme and templates in those (non vB forum) pages.

I have done this sort of thing in the past with some of the 'free' forum/Bboard systems that are out there simply by loading their primary header file and authentication file which loaded their templates and themes, but I really dont' want to trust those systems for business use in the quality and support that vBulletin might offer, and also, they don't provide user-group functionality.

So, I recognize that vBulletin does not package itself for the use that I described, but I would like to ask if anyone has done it, and if they can answer some of my questions, because I think it is something I would like to attempt.

1) Can you call (via include/require) a vBulletin file that would give access to showing vBulletin templates & styles on non vBulletin PHP pages?
2) if so, how many queries to the database would this entail for a
(2a) visitor who is not logged in and also for a
(2b) member?
(3) Does this void a vBulletin warranty or terms of use or service? (I understand it is not supported, but is it restricted somehow?)