bbPress.org

1) Yes, you’ve heard correct that project is almost dead as no development is taking place for weeks. Also, more chances are that it will be converted into a WordPress plugin (but some methods might be made available to transfer your data from the bbPress install to the plugin).

2) bbPress 1.0 was almost a rewrite of 0.9, so a lot of code changed and the plugins became incompatible. _ck_, a major plugin developer and contributor to the project left because the project was not getting attention from months. You can check her website – http://bbshowcase.com

3) Can’t say anything about the timings….

4) That has been reported in #1181