Using the health tokens is entirely relative. My wife prefers to start with enough counters to represent her hero's full life, and take them away as she gets hit. I prefer the opposite way (applying tokens as I take damage). I just feel it gets less hairy that way. Especially when it comes to the villains. It's much easier, in my opinion, to put a 25 counter on the villain than having to break up every 25 that I break through.
The heroes you mentioned are all good, except the Argent Adept. He is, in my opinion, the hero that's most difficult to master, and he's almost entirely built to be a support character. Granted he has a ton of different abilities, but I admittedly had a little AP trying to figure out which of his instruments/abilities to use on a given turn at times.
The Chrono-Ranger is by far my favorite (from Shattered Timelines). Put the Ultimate Target wanted poster on the villain, have someone like Legacy and/or Ra boost his damage, and watch the villain crumble in no time. Nightmist would be my second favorite. I know some disagree with me, but I think she's a more extreme version of Absolute Zero (Higher risks/rewards). I haven't played the alternate versions of any of the heroes, so I can't really comment on them.
The heroes you mentioned are all good, except the Argent Adept. He is, in my opinion, the hero that's most difficult to master, and he's almost entirely built to be a support character. Granted he has a ton of different abilities, but I admittedly had a little AP trying to figure out which of his instruments/abilities to use on a given turn at times.
The Chrono-Ranger is by far my favorite (from Shattered Timelines). Put the Ultimate Target wanted poster on the villain, have someone like Legacy and/or Ra boost his damage, and watch the villain crumble in no time. Nightmist would be my second favorite. I know some disagree with me, but I think she's a more extreme version of Absolute Zero (Higher risks/rewards). I haven't played the alternate versions of any of the heroes, so I can't really comment on them.