With reference to the actual topic, here's my thoughts on a few things:
Life Settings: I like the 270 HP setting. 240HP is ok-ish too but some more powerful moves and throws/OH would need to be tweaked. 300 HP is too high plain and simple. You don't get as much damage reward for your combos or moves, and higher life = more sloppy and scrubby play leading to boring matches.
Guaranteed Damage: If I'd have a choice, I'd leave the SE glitch in to allow for more combo setups but I would like there to be more unholdable stuns overall. I agree that Advanced Holds and Parries should not be allowed from stun (i.e. Critical Holds).
Stun Threshold: I would probably reduce the critical stun max by a smidgen to allow for one less guess before going for a max-height juggle. If the threshold is too low, Critical Bursts will need to be readjusted. Luckily I main a character that can launch off a single stun or CH.
Frame Advantage: It would be nicer if there were more moves that were safer or advantage on block, to lead to a better flow of offensive pressure, but the hold system kind of undermines that in a way.
Sidestep and Movement: Sidesteps and general movements need a lot of improvements. The sidesteps are awful to put it lightly. They're slow and don't step the whole string. They need to be greatly sped up and need to step the ENTIRE string like pretty much every other 3D fighter. Stepping a string just to get hit by a retrack from a button-masher is annoying as fuck. Backdashing also could use a tweak to allow for better whiff-punishing.
Furthermore, low attacks, including low wake up kicks, should NEVER EVER be able to hit someone that uses a jumping attack or are in a state of TJ. It's just plain stupid. Another thing also is I think it's dodgy that OH's that are highs can beat out TCing attacks. Jumping OH's also should have 0-tracking ability.
Good Tool Sets For All Characters & All Playstyles and Characters Effective: I agree with this. I would like the roster to be as balanced as possible while maintaining individuality. Let the character's personalities shine through!
Minimize the Power of the Hold: Yes please! Although I love that holds got nerfed in DOA5, I still find that they get abused and spammed. What I'd either like to see are holds getting reduced to only parries (like Pai's) or throw damage getting buffed. IMO, only the grapplers and pseudo-grapplers should get holds and the strikers should get some variation on the parry like Pai. However, this may undermine HC-Throw setups so I would settle for a mild nerfing of holds. I want damage from strikes and combos, not hold spamming.
Overall, I'd like to see DOA's movements (backsteps and sidesteps) improved along with more refinement to TJ's (i.e. better low evasion), and more frame advantage moves. I also would prefer if OH's would be exclusive to just grapplers and pseudo-grapplers.