Re: Why is integration so troublesome?
If you are getting anonymous users, I suspect you haven’t setup integration properly and they are not sharing the same user table.
As far as your other observations (and I felt he same way in the beginning too) you have to realize that (easy) integration was only a priority starting with 0.9
(you can see how complicated the process used to be under 0.8 here – note most of that is not needed now)
Until 0.9, bbPress was just something that ran wordpress.org for Matt and there was no attitude to make integration work. There were tons of problems with usernames etc. and all integration had to be done manually with lots of plugins to fix things.
Then attitudes changed when Matt got funding and decided to use the bbPress code to power TalkPress (essentially forums for users on WordPress.com) Sam and MDA have done a great deal of work to make integration work better but it definitely has a way to go (and should become painless and super-easy IMHO).
So 0.9 has made integration easier but keep in mind bbPress is not even 1.0 yet, so officially it’s not even a released product. The radical cookie changes in 2.6 will take awhile for bbPress to catchup, it’s always been that way.
ps. if it’s not obvious, I am in no way officially associated with Automattic/WordPress/bbPress. Just a plugin developer. And I am not paid. My opinions are definitely just my own and not any kind of official statement.