Mo Metal Mo Problem - Didn't even sweat wasting 3,000 metal in a single match
You will need to play as PHC for this, since Substrate no longer have a resource cap. All you have to do is allow your metal to reach the cap, then when 3000 metal gets wasted (i.e. produced when you are at max capacity) and you win the match you will get the achievo.
"Not too proud" Won a skirmish with a handicap? Ermmm where is the handicap option?
I'm not sure, I did get this on vanilla. Try the resource bonus option in the player list, perhaps setting this to give you more resources.
As for the 2 unfair team achievo's, I would like to know that too.