I've played a bit of it and have been winning against each chaos player. But I'm not sure if I'm Doug it right. How does one apply early game pressure after capping the tower. I rush in my bombs and do damage but its a hassle keeping crawlers from being bombed unless I keep a crawler in front of the gate.
When does one go into mana?
I usually get my deads before my opponent and apply pressure after rushing bomb support into enemy deads to tank and give extra dot.

Ok, here we go..

If it's a short go two cats two miners then right into bombs and miners if it's medium then go with an extra cat and then bombs. Try to take tower and take the advantage. Keep making miners and pressuring with your bombs. Be smart to where you use em' and start going for mana at about 1:30. Go deads if it's neck and neck, go wings if you're winning and have a large eco. You want to have hustle, charge, either poison or not depending on your macro. Your macro should be influenced by what's happening, not by the specific map. Tower spawn is always good. If you go deads be sure to incorporate bombs here n' there to deal with wings and or deads, same if you go wings. Keep pressuring and getting in there, fall back if necessary. Bombers are essential in wing v wing play, and always manage your eco.

That's the jist of how it goes, not hard, just practice.