I agree with the guys that I do not see one eye being better than the other but I believe you, especially about seeing no flash reflection from one eye. Anyhow, yes cloudy eyes is not a norm but IMO in good conditions it should improve and go away on its own. It is not necessarily an infection (although could be) but may be stress, shipping/rubbing, difference in water, etc.
I did read of some keepers describing how Melafix cured their fish's cloudy eye problem. A bit surprised about it though. I'd use a hardcore antibiotic, not a superficial, mild anticeptic like Melafix but I also believe anything's possible and experimenting pays off.
Fins will heal no problem. I don't think you got mistreated by Shark Aquarium but if you do - call back and talk to George personally. I found him being a great guy and he will help you out if he finds you are right.
$100 for 12" is good. Mine for $80 were ~9"-10" and that was, as I said, ~3 years ago.
A few last times I'd been to Shark Aquarium, they had like a dozen of these guys, smaller ones, 6"-10" in one tank and bigger ones separately.
As I wrote, my three loved fleshy foods. There is no need whatsoever to gamble with live. Just my $0.02