well... i have not a good answer for your question about the munchies, because when im stoned i eat to my heart's (or rather stomach) content... i hardly do any physical exercise, and, surprisingly, im skinny! Its a mystery for me...

As for the another questions... if you want to get much stoned with less weed, and want no problems with smell, i suggest you to smoke hash oil. It can make your weed last at least 5x longer, it makes much less smoke, and the smoke have only a faint smell, very different of weed.
And the high is HIGH... :stoned::abduct::thumbsup: