1) Cyclone: I really like the initial design, i hope they do not scrap the cyclone. What i feel might work for the cyclone is that it targets the ground only. And by that i mean not only can it only hit ground, it cannot 'target' units traditionally but you have to aim at where they might be going, similar to the upgraded roach.
This would make sense to me as you get to keep the intense micro battles, and allow protoss tier 1 to actually stand a chance against it. Stalkers and Cyclones can "dance".
2) Herc. Honestly, just bring back the firebat and give it a hook/splash damage upgrade. You get to please the old fans and bring something cool. I honestly do not see the difference between firebat and Herc.
3) Warping Battlecruisers/ Picking up sieged tanks
Those 2 concepts are really interesting to me, i would like to see how it goes before making changes to them. They could do simple changes to it like the sieged tanks can be picked up in siege mode but when dropped from the medivac they need to re-siege up or something like that. (A simple change that makes sense and stops the nonsense leap frogging micro)