brine shrimp betta

I was under the impression bettas loved frozen brine shrimp
I got some today for my females they loved them, ate them right up, none of
my males were interested, do they have to get used to it if they never had
them before? also how about the gourami will them or the angels like them as
well?

One more thing I stopped in today at petco and they had a goldfish the one
with the bubble checks pretty cute little things, it had one of his checks
deflated, guess it got injured, I felt bad and was going to get him because
the girl said no one would buy him because of it which is understandable,
but I then noticed he had tail/fin rot, I ask her if she would QT him and
treat him for the rot then give me a call and I would come back and get him,
I don't have the space at the moment to QT him, she said sure she was pretty
nice and seemed to care about the fish surprisingly, she said other wise
they would more then likely get rid of him (yikes I think she was saying
kill him) she said all though she did not know a lot about that type of
goldfish, she did not think his bubble would grow back, will that cause
problems with balance, swimming? and was she right in saying it wont grow
back?
just wondering, I will probably get him next week if she is able to treat
him, I guess I should of just got him and did it myself but Luke gets
attached to them and if he dies I would feel bad.

nik