To: Big Jake
Hello,
Unfortunately, there is no such feature as voice remover in AVS Video Editor. The only thing as I can suggest - is split your audio track into parts using Split buttons and mute the parts which contain unnecessary words, comments (right click on audio clip>Mute).
As for increasing/decreasing sound level - you should use Audio button, where you can find Amplify, Normalize and other audio effects. Find more details
here.
Regards.