Re: cookie sharing between wp and bb
'/bbpressfolder/' (I presume),
'wordpresspass' are not placeholders for your actual value: they are the literal values you will have there. Check your wordpress cookie; those are what they use. A part of the structure is:
wordpressuser_site-unique hash=your username
wordpresspass_site-unique hash=hash of your password
With his settings, bb should now be using that too.