Noted about the mana. We received some feedback about putting the mana cost and CD at the icon level, so that it's visible without doing a mouse hover, might be a good idea after all.
About the "natural talent", we're toying with the idea of, essentially, having each character have a sort of sub-class in the form of the 4th (or 5th) skill slot, a completely passive skill (similar to how oppressive aura works now) that gives this kind of cross-cutting effects. What you suggest might be a good fit for such things.
About the buffs getting crowded, also noted. Indeed the combination of buffs and effects is a core part of the game, but we absolutely want to keep things as streamlined as possible. So far we've toyed with the idea of capping the number of active skills of each unit to 3 rather than 4, and/or making the mana bars of enemies not visible or even removing the health bars, so that players don't have to calculate numbers to the exact extent (because they can't compare with the current HP), to encourage playing more with their guts/quickly
Thanks again for the valuable feedback, it is really of the utmost importance!