Hello I just wanted to put all my ideas in one spot for the time being. Before I suggest I wanted to say the new patch is a nice breath of fresh air nice to see more than 3 viable openers. That being said I do think there are a few issues that need to be addressed.

Main issues:
Firstly Vikings are way too strong in the early game for the minimal amount of micro required to use this a move elite you out trade pretty much any other ground elite. On top of this in air mode, they perform well in the mid-game since they are effective at killing air elites and softening air mercs for most engagements. I think nerfing their ground attack rate or decreasing the ground range would be a suitable change.

Next, Destroyers seem to be the strongest mercenary in the game potentially. Their high movement speed combined with large splash attack makes them very strong it also seems that their intended counters have trouble actually countering them and tend to trade even with them at best. My suggestion would be to decrease their health scale or nerf their splash slightly this would incentivize less blind picking which is great.

Another unit I would like to see changed would be the Lurker. I think with Phoenix being so important to the meta there is very little room to outplay or do anything with Lurker. I would suggest increasing its range by 0.5 or 1 and allowing it to use its stun ability while burrowed.

Side issues:
This may be up for debate but I feel as if untouchable marines have not been used at all recently. This is likely due to the fact that rapid fire got buffed and is a direct counter to them. What I would suggest is that untouchable gain some sort of other reward besides just the dodge maybe increased armor scaling by 0.5 or less from the point that you buy the upgrade? Its the hardest major to tech to so why not give it something else?

Another concern of mine is that Dark Templar feels very underwhelming the stun only lasting on the elites and heroes for half has really hurt its viability making it nearly unviable. My suggestions would be to increase its stun on elites/heroes to 75% of DTAs.

Speaking of Dark Archon it seems to be one of the worst ultimates in the game right now even in ultra late game. I believe that Phoenix is the main root of the cause since a single lift spells death for it most of the time. It lacking the range that most other ultimates have is what really hurts it. I would suggest giving it some sort of reduced duration when its lifted by Phoenix maybe 75% of the normal lift time? This may give it an edge to other ultimates and allow us to see it used more often.

Thanks again for the time put into the latest patch.

I agree with these changes, and would also like to add some buffs that can help bring units that are never seen into a more playable state:

Oracle:
Increase range by 1.5

SV:
Increase time warp duration by 10% with the upgrade and increase the size.

Mini thor:
Can either slightly decrease cost, or make their barrage go of faster and affect air.

BC:
with so many ways to stop yamato, i would recommend just making yamator faster to cast and seeing how it does after a bit. Its 500, and the yamato takes a year to go off, I think if it was a bit faster players might try using it again.

Diamondbacks:
Just a slight damage buff should do.

Mothership:
Decrease cost to 350.

Lurker: give +1.5 range and make it so it can use stun while burrowed.

Odin:
Increase its starting splash vs air, and increase its final aoe splash vs air. Right now its supposed to be the ultimate anti air hero, but just getting corrupters is far more viable. Would like to see when people have air on both sides they go odin, as it should be instead of just getting corrupters.

HK:
Increase their max upgrade attack range by 1.

Lurker:

Remove Air attack
Immune to lift when burrowed
Decrease Range by -1

don't agree with vikings being nerfed, I think it's just all the other openings aren't great so the amove vikings are an actual option. They're amove but you'll always get more value with reapers.
destroyers 100% too strong vs their counters (besides brutas, but brutas are the least microable arguably worst merc).
lurker more range would be pretty good so the lift just disables it not kills it.
untouchable marines and combat shield marines are both really bad and need some sort of change
DTA having a longer void might be another change, just disable a big chunk of their army for a while so it's keeping with the assassin style of dt.