Instead of NERDTree you might want to try Vimpanel, it's based on NERDTree but much more evolved, and instead of using :bprev/:bnext you might want to try Bufstop, it uses history instead of the buffer list to get you to the previous buffer. I made these to get around some limitations for some plugins that everyone seems to suggest.

https://github.com/mihaifm/vimpanel https://github.com/mihaifm/bufstop