Then what is the use of "Sie" here??
The sentence is formal, if you were talking to a friend you would say "Wünsch mir Glück", but in formal speech, the Sie is needed in the imperative
'luck' is not an 'object', so no 'a' is required.
To expand on that - "luck" is not a countable noun, so you wouldn't use "a", but it is indeed a noun, abstract or not :)
"Wish luck for me" is wrong?
That sounds quite unnatural in English.
There should not be "a luck"?
Although it is an awkward sentence in English, I think that "You wish me luck." should have been accepted.
I disagree. I really think it changes the whole meaning of the sentence if you include the "you" at the beginning, or at all for that matter.