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"?