The slower it burns, the more THC is lost.
I could see that would be the case if you let it idle, but a decent sized slow burning blunt cut between a few people should be pretty efficient. Slower burning is better because while it is idle it doesn't burn away quickly. I would say the faster it burns the more is lost, slow burning blunts last longer = more hits = stronger high.

As for honey, don't bother letting it dry that sort of defeats the purpose of putting it on. If you put too much it will make it kinda harsh to smoke, dab a little on your finger and spread it all over. When I say a thin layer I mean it should be glossy-looking but you shouldn't see any globs of honey or anything.