Yeah for sure the game takes some time to really understand it, the game is focused on the AFK aspect of it(relaxed gameplay). It does have a lot of strategy involved, but not that hard once you get a grasp on it.
By combos you mean the heroes doing their Ultimate Skill? That can be on Auto or as you have it on Manual. What you were doing was activating their Ultimate, timer is not shown(sadly) but heroes replenish their energy(used for Ultimates) automatically or using buffs by other heroes Ultimate(like support heroes).
Let me know if I understood your first question right, Im happy to respond.
Regarding the all heroes page, there is one and it shows all heroes available in game at their max strenght and max ascension. Not all heroes can ascend all the way since there are 3 tiers of heroes. In the screenshots I show where the tab is.
That lock can be from a lot of things, but most of the time is where your heroes have only 1 life and once they died, they cant be used again unless revived. But thats on other game modes... whats confusing me is that the image youre showing is from Campaign where thats not suppose to happen. You somehow did that on purpose? Is that what you meant by "I realeased that characters can be locked or something"?
Again I hope I understood everything right, english aint my first language. I'd be happy to respond again. Thank you!