Well since we are throwing in our suggestions for balance, here mine go:
Nerfs
Panzer - lower magazine size to 16 or even 14. This would significantly lower her burst without affecting her overall damage too much. Heroes still die incredibly quick to her in the first 5-10 seconds of a match, especially if they are energy. She is the reason the Ifrit/Flatline combo is so powerful, because she’s the only DPS you need. As soon as her shotgun is full she basically kills a hero each time. Tighten up her shell spread a bit to help compensate for lower clip size.
Dogface - reduce damage by 10% when his silver and bronze are going, OR reduce clip size again to 16. His burst is still pretty insane but his damage outside of it isn’t anything special.
Ifrit - Couple options here. Either make Showtime have a 25-30 second CD and last 10 seconds (so it’s not up half the time), Reduce it’s duration to 5-8 seconds, or make the disorient only have a chance to affect each hero (or make it randomly affect 2 heroes instead of the entire team). If nothing is done to Showtime then his plat needs to be nerfed. 20-30 second revives would be much better than 15 seconds and give you some time to actually kill him before Flatline pops back up. Of course they could just nerf the max number of heroes revived to 2 or 3 as well.
Caine - make his shields have less health, or slightly longer CD. OR, allow some damage to still go through them (say 25%?). Being able to instantly give a hearo with 10% or less hp a 100k shield is rough. It especially sucks when it reduces damage, silences you, and heals once the charges are lost. Maybe make Counter Measure not flinch your hero?
Heimlock - not sure about him. Maybe reduce his hp and the hp he grants to allies? He just got nerfed so I am not entirely sure he needs anymore.
I don’t think Nightingale or Flatline need anything else. Both are extremely squishy. Night had her group skin heal nerfed twice in a row and her single target heal buffed so I think shes in a good place now. She can heal a group for almost a third each what her single target heals for.
Buff
Maven - I think her DPS is decent, but her Vampiric Cloud is terrible for PVP since it’s easily avoided. Maybe make heroes hit by it also disoriented, or slow their movement speed by 80% for 4 seconds so it’s tougher to get out of if you do get hit by it? Also, Maven needs an hp increase. Part of her problem is she dies so damn quick she can barely do any real damage. Add 100k to her health and 500 armor (still significantly less than Panzer has) and she would still be sort of squishy, but last long enough to do some real damage.
Clyde - similar to Maven, his DPS is decent enough, but his hp is garbaged. Give him a big boost in hp and armor so he can actually live long enough to do damage. Also, half his abilities only have a 50% chance to land. That’s leaving a lot up to fate. Half the timehis bronze skill hits for a lot and stuns, the other half it does absolutely nothing. Maybe increase this chance to hit to 80% on his skills and lower the damage by 10-20% to compensate?
Halloway and Hivemind - I like the suggestions for these heroes. Have them both start with a drone/clone up so they can get to their max potential faster, rather than be focused down almost immediately.
Sapphyr - Increase her health and armor… by a LOT. She is so squishy it’s not even funny. Noticing a theme here? Also, increase her damage slightly and make her plat skill have at least a 5%, if not 10% chance to work.
Kunoichi, Odachi, and Heckler - same with Sapphyr, they desperately need a health and armor increase. I don’t find their damage lacking at all, they just die before they can do it.
Gammond - make Last Stand not so terrible. Gammond is rarely the last one alive, and even if he is the bonuses aren’t that great. Maybe give it a 20% chance to go off after each hero death? That might be too good with the current Ifrit/Flatline meta though. At any rate his heal could use a boost to maybe 10k per second and last slightly less to 15 seconds? Kill Shot could use some energy damage on it, say 20-30k or so
Matador - change his heal back to 10 seconds, 3 seconds at 52k per tick is ridiculous. To compensate reduce the amount to 30 or so per tick. Also increase his damage across the board. When 2 of his 4 skills are reliant on damage and getting killing blows, it’s counter productive to have him do such pathetic damage. Either make him a decent damage dealer and keep everything as is, OR rework his gold and platinum skills so they aren’t reliant on damage. His platinum could at least effect the entire team. A tank hero with high hp and armor that doesn’t have a reliable taunt or utility for allies is pretty much worthless.
I think this would give us a nice round roster of 20 or so heroes. Of course there are a number of others who need work, but this would be a good start and some quick, easy fixes.