Seems like a good direction to change the meta and pace of each round.
I like the increased scaling of late game upgrades, to increase the importance of teching. Though I'd scale the power of marine Pres purchases instead of Arms Lab upgrades, which are already over-emphasized.
Marine Hand Grenade capacity should require an extra research as it is very powerful.
Contaminate would be more counterable if it was redesigned as a Drifter ability.
With increased Pres, the game could be more "fun", as it shifts toward countering the enemy team's composition, rather than struggling to keep your weapon/lifeform.
Looking forward to playing your mod!

neat