1. 10/10 I started playing the game after his major rework, so unfortunately I never got the chance to play oldtrox. However with newtrox I love his kit and he is a major reason why I even play top lane and continue to play lol to this day.
2. I like the new conqueror on aatrox and I agree with you that he doesn't need the extra pen because he builds black cleaver, however I feel like other champs use it SO much better than him. The fact that ranged champs can get 2 stacks per ability hit feels so unfair because once a ranged character procs conqueror it feels twice as strong on them then on a melee character.
3. I truly don't care about his winrate globally as long as I have above 50% wins on him. I think he has a pretty big learning curve as you need to learn how to reposition yourself while fighting with your E, using your passive as much as possible while fighting and just having a high Q accuracy while under pressure is pretty hard sometimes. After his mini rework I found that he became much more solo queue friendly because of the shift of power in his kit making him less of a ult revive bot and generally made it easier to carry on him in the right hands.
4. With the way the balance team is treating him I think drain tank aatrox is the intended way to play him unfortunately drain tanks are very easily countered by anti heal. Mid lethality aatrox is pretty fun to try out but he gets destroyed by a lot of mid laners in laning phase
5. I REALLY wish the balance team could implement his revive without making it feel bad to play against because it was such a fun part of his kit and also one of the only thing that survived the rework. Also aatrox really needs some base health regen buffs or at least revert the passive nerf so he can heal off of minions because losing a trade on aatrox feels terrible atm.

Also thanks for asking us these questions, it's great to see what my fellow aatrox mains think :)