After giving this some thought, it could definitely work as a live-action, but I would be more at ease if it was Disney/Marvel that snatched it up. Personally, I think they're the only ones capable of grasping MHA's core. Much of MHA's influence was based on Marvel's works (with a dash of DC), so if they were the one that got the rights, then I think they would be the ones to truly "get" MHA's core.
Also, I don't mind if they don't try to replicate the character's likenesses.......... There. I said it. This is mainly because much of MHA's cast are based on typical hollywood archetypes in teen dramas. You have the shy awkward nerdy kid, the girl next door, the straight-laced student with borderline OCD, the jock bully, the emo kid with daddy issues, the rich and genius of the class, two goth kids and the party animal/social butterfly.
They could be played by any actor, and I wouldn't bat an eye whether they're being played their original ethnicities or not, so long as they keep their characters intact. But I do of course hope they'll still have a good mix of asian actors/actresses thrown in, such as Tsuyu.
