It should be 'your' not 'you'
Correct. Report the error, please.
'Your blouse is very beautiful' not accepted, but I have never heard of a man's shirt being called beautiful unless it was very camp.
Why do you think this refers to a man's shirt?
It should be 衬衫 can be shirt or blouse. I think "top" is also ok.
In Chinese, can this sentence be directed to a man, or can it only be directed to women?
"Your shirt is very pretty!" should also be an acceptable answer.
Your dress is very pretty fails as an answer. Beautiful works. Doesn't make sense to me
I side with you on this. I've mostly known 漂亮 as pretty rather than beautiful.