The distance between main base and ramp is huge. I suggest you to move them to the left/right map edge. Look at GMCS. And fix gas issue at mains.

impossible to stop terran push...

Ok, Ill fix the ramps. How would you suggest I make it so Terran cannot push through the map?

Unbuildable terrain, and make the distance between bases a !@#$load longer.

perhaps try utilizing the lost terrain in th every center which is only there for decoration or something, that space is much needed for flanking.