Add these to the units section of alphax.txt
AI Super Formers, Speeder , Formers, Scout, 9, 1, 0, None, -1, 00000000010000000000000001
AI Colony Pod, Speeder , Colony Pod, Scout, 8, 1, 0, None, -1, 00000001000000000000000000
These are super clean formers on the rover chasis(2 moves) and rover chasis colony pod with defense against worms. Each cost 1 row of minerals.
Don't use them yourself, but let the computer use them. The AI will cover the map and work improved tiles!
RE: Nerve gas.
There's not much you can do via editing text files. You could move nerve gas to a later tech or disable it. Its probably best not to use it if you want to make the game harder.