A mighty fine choice from a switched on character.....putting the FAA before the crabs.
Eyesight/mild asthma could be a big problem, but the only way to find out is to apply to join and attend the medical.
Posh or not is irrelevant and unlikely even to be noticed. What matters is ability, attitude, aptitude and character. Even if you don't get aircrew there are a whole host of other interesting jobs available.
Check out other threads on pprune.
F