just a couple things i've noted after watcxhing the above:
Bad drive meter management, you burn yourself out or shoot OD FB's from full screen.
You put yourself into the corner a lot and walk backwards
You're right, you whiff a lot of big buttons that are wayyyy out of range and get punished for it
Pressing a lot when your minus, i know above you said you find yourself in block strings a lot, best thing to do is go into replay straight after the match when you feel like it was a pure block string and look at the frame data, do replay takeover and find out what you can press in those situation.
I think in all 4 replays above i counted 2 maybe 3 anti airs, if you're going to play a FB game you need to improve this and change up your fireball patterns and distance, as it becomes easy to read and people just punish you for it
Yeah i feel like you don't really play neutral that much, you kinda just walk back and throw the odd fireball and try to skip neutral with demonflip dive kick or air fb etc... ST.LK is an insane button for Akuma in neutral and his F.HP, CR.MP, F.MK, CR.MK etc... is also really good, i didn't see you really use these in the above and instead kinda relied on ST.HK (Which is such a trap button for Akuma players and a bad habbit to rely on in neutral) and whiffing ST.HP
You give up corner pressure a lot when you do sometimes get them to the corner, you just walk back and throw fireballs and let them out for free. The corner is where Akuma is the strongest and you have to apply pressure on OKI. Such as Throw loops, Tick throws, ST.MP leaving you +1, charged FB leaving you +2 etc...