Re: holes in that are punched close to the rim are bad ?
I've been smoking for years and I have always poked holes right up to the rim and follow by poking 3 more concentric circles all the way to the middle, for a total of 4. Always gives me a great sessions lasting anywhere from 1.5 hours to 2+ in a small phunnel bowl or vortex bowl; I've never had issues doing it this way. Tiny holes poked with a needle are the best in my experience.
As far as burning tobacco, that'll only happen if you pack the tobacco too high so it is in direct contact with the foil and thus the coals.
I don't own anything cos you guys bought everything!