Hi!, Again....Some times you loose Bass & Drums when removing vocals. They stille there, but almost inaudible.
I used Cakewalk ProAudio 9 to open VR (Vocal Removed processed with PKPlus) wave files, then adding a preset equalization (you can make your own settings also) to Boost the Bass & Drums. It fattens a little the bit you left of the vocals, but It's a small price to pay in order to have a solid VR wave. You can always adjust the Equalization for optimun results.
Also, with the same program, you can lower or upper the Pitch resulting this in a Key change.
Maybe Adding and Equalizator, and a Pitch Shiffter will solve many of the problems exposed here. How to do it... It's up to you guys.