those meta gems.. What does it mean when it says it 'requires alteast 5 blue gems' or 'requires more red gems than blue, more yellow than blue'?
That you either need a meta-socket or 5 blue sockets? and a piece of armor with 1 red and yellow socket but no blue, or two red and two yellow and one blue?
As far as I know, those "Need more red gems than blue gems" etc thingys is just to get the Gem-bonus on that specific item, which almost every time is just crap.
False, Meta gems are special, they only fit in meta gem slots (found on head items only afaik) and other gems dont fit in meta slots. The requires at least x gems of y color or more of y then of z color means that in the rest of your gear you should meet those requirements.
Dual color gems count for one of each color i think.
Failing to meat the requirements on the gem will result in it beeing inactive (you do NOT get the bonus)
the armorsmith final armor also has a meta slot afaik