I just installed BBM again and I cannot duplicate this conflict in regular posts.
In the editor for regular posts, both BBM buttons and VW buttons appear and work as intended. There is no issue with icons disappearing either.
In the editor for wiki posts, VW buttons appear and work as intended. BBM buttons do not appear; this is a bug. In fact, not even custom XenForo BB-Codes via XenForo's manager will appear. This is now fixed in the next release. Even with both BBM and VW buttons appearing, there was no conflict which prevented the buttons from working.
I am marking this as fixed in the next release, since the missing buttons should appear starting with 4.0.6.