There's an option to clear target if you click somewhere else, forgot where but you should probably check that out.
You can't use 2 abilities at the same time, they generally have to play short animations first(they can be played during the GCD of another skill, but you generally can only fit 2 oGCD per GCD, and sometimes depending on which one, you can only fit one without clipping your next GCD). You can macro a delay, but since the minimum is 1sec, it's garbage. You can just mash the key and do it that way, generally works. It's nowhere near EQ2 bloat though, it's like about 25-28 actives even counting the heavensward stuff. A few classes have more than others(fucking scholars need almost 3 bars due to having pet stuff and no really poor skills like most other classes, though I guess you can cut Ruin 1 now so that's nice) but warriors are not one of these. you might argue that's too much but I find that acceptable, that's 2 bars and a few more that you can click or macro if you don't want to keybind. I know wow did large reworks to compress it over the years, but even by BC I'm pretty sure most classes had 2bars also. Only thing you'd want as a WAR is a hotbar swap when you go into offensive stance that swaps Inner Beast and Steel Cyclone with the DPS skills that do the same thing, Fell Cleave and whatever the other one is, saves you 2 keybindings.
Also unlike EQ2, the abilities are really not the same. You might want to Internal Release but not Berzerk, due to the downside of berzerk activating at the wrong time(it's dispellable but as a healer, fuck that noise). That's pretty much the only thing you'd want to combo, defensive cooldowns are meant to be staggered, and if for some thing you do need them all, you can do that manually by clicking them. Unlike PLD or DRK who need to use cooldowns quickly, the only WAR cd you need to be quick to hit is Inner Beast since it's up so often, and then you can judge if you need more while you're in GCD for that. Tbh the long GCD should make it very easy to use abilities even if you don't keybind everything, that's kinda the point.
Pretty sure you're also misunderstanding what hard mode means. It doesn't actually mean it's hard. There's no challenging 4man content in this game. Hard mode is basically heroic dungeons in wow, a max level version of a leveling dungeon. However unlike wow, they're actually different dungeons(well last time I played wow at least, it was just like the same dungeon with a few new mechanics and sometimes one new boss), but they're still dungeons and you'll still destroy them. It's kinda weird nomenclature but that's how they go, hard mode is simple max level version of something else. The actual hard stuff is called extreme(for primals) or savage(for coil) and there's no equivalent for dungeons.
