Re: No search… how to uninstall
bbPress’ table prefix should never be the same an WordPress’. That will cause many problems, as you may have experienced.
bbPress uses the following tables. Don’t delete the ones marked with a *, since WP uses those too (hence the problem).
forums
posts*
topics
topicmeta
users*
usermeta*
tags
tagged
These all look like bb_forums (or whatever bbPress’ table prefix is in your case) in your database.