IMO, all that needs to be done to fix Hypercharge is to reduce the animation lock of Heat Blast, Gauss Round, and/or Ricochet. It seems you're intended to alternate between heat blasts and oGCDs, which I find fun. You have about a second of leeway for ping to delay things without losing a heat blast, but still any delayed GCD throws off the rhythm and feels bad.

I agree that the recast timers for Hot Shot, Air Anchor, and Drill need to be made more noticeable. Unlike abilities, their icons turn dark every time you use a GCD, so it's easy to miss when they're available. I've stuck icons for them in the middle of my screen and still forget to use them.

I don't know what would be a good solution to this. Maybe they should have a slightly different icon appearance when ready to use, similar to the dotted border for combo actions. Having them come off cooldown half a GCD early might also help, and it could alleviate some of the issues where hypercharge misaligns the GCD from these cooldown timers.