Admittingly, I never played annex multiplayer beside 1 coop match with a non RTS player, lol i had to tech him basics of movement, and I myself is not a multiplayer rts player so i have no idea how veterans would play this game. It would be nice to see how others pay it and get more of an idea of how game should be balanced.
That being said let me answer some stuff.
Technically I consider annex having 3 tiers T1 Starting units, T2 Advanced Weapons (tank, mortars, gunships) , T3 Units requiring silo or tech lab (mrls, walkers, harriers, guardians).
Yes advancement to tier 2 is more of a speed thing, Tier 1 is more about reconnaissance, and getting your base up and running. Upgrading to tier 2 after your first factory. Tier 2 is your base gameplay, as you will use these units till end of match, tier 3 are your closers, and heavy hitters, and weapons based on what strategies you want to use.
Claymore is right about the turrets they are powerful but more defensive you get the less military size you get. ANd btw all units take 1 population point EXCEPT Harvesters, Bunkers, and EML Turrets. The more harvesters you have the less your population count could be so don't create a huge amount.
Resource management is different, as i did not want it based on expansion. You start with your refinery, and basic workers which give you a trickle of supplies, until you get Harvesters, which are much better at carrying credits for farther crystal patches. The idea is that instead of you building small bases around crystal patches you have to send harvesters outside your base parameters, leaving them vulnerable to attack. So making it a more of a risk and reward system.
Ps Vs Ai I've only build a maximum of 3-4 harvesters, I was surprised to hear 6-8 being used. Ill get around this my making them size 1. Since they will be size 1 maybe they will be upgradeable from workers.
I want resources to expire fast, but maybe ill increase amount per crystal to 45 or 50 (currently 40)
Strikers are one of the few ground units that could attack air units, doesn't need anymore encouragement than that
I've been debating the Anti air defense for a while, but with strikers, and harriers there really is no need for them. perhaps anti air units need to be stronger?
As for hero, there are two icons in the refinery because there is no better way to create an "OR" requirement, meaning you need EITHER a tech lab OR a Silo to make Hero. As such one icon is for Tech lab requirement and other is for Silo The different structures also gives you access to different super weapons, eg Silo grants nuke ability, Tech Lab gives you beam attack ability. Speaking of witch, what are your opinions about the superweapons? Are they balanced well?
