Regarding "correct" barre chords versus "thumbing the bass string(s)"....

Barre chords would be a lot less trouble if we were born with perfectly smooth slide bars on our hands instead of these damned wrinkledy fingers! When I make a barre F chord form "properly", the B string often winds up in the crease of my second knuckle resulting in inadequate down-pressure and a buzz. This is not a real problem when playing rhythm with a flat-pick because all the damping, vamping and chopping make the tone of a single string a non-issue. But if I'm playing with fingerpicks where each string is supposed to be heard individually, that buzzy string really calls attention to itself! So, when fingerpicking I always use a regular 5 string F chord form and catch the bass note with my thumb. It doesn't look as "classical" but it sure sounds cleaner.