JADM

Depending on what you have linked from your vBA homepage, yes it may be facilitating access to your deeper content, faster. However, most likely you are not listing all your subforums now from within the homepage (as the forums are no longer the main page), so spiders get to access subforums from a "second click" location in your overall site structure. In theory, you want spiders to access your most valuable content faster, if possible with a "single click".

That said, you might want to add a list of all your subforums to your vBA page or, if it's too extensive, you might want to add the most important ones.

I don't think, that Google likes vBAdvanced and surely it will have bad effect on your forums crawlability, as Juan said. If you have a rich content of forum homepage and advanced subforums' system, it will be more useful for you not to install vBAdvanced.

hows vba together with vbseo ? dose it make google ban you /black list your site ? just a thought...