My husband (Latvian) and I married in Serbia, after dating nearly two years.We litteraly flew there and two days later we were married

On this forum Ive read that this could be an issue due to 15 day residence requirement in a country prior to marriage and it can lead to application refusal. Could this really affect my RC application form??
My husband is exercising his threaty rights in the UK, and has never claimed any benefits nor public funds. We are both in the UK, and as one of the members said here, we did not get questioned at all when we got back from Serbia. This might be due to having valid student visa which expires in beginning 2014.
When I apply for a RC, will my student visa be cancelled?
Does the 6 month rule start from the day UKBA recives my application or from the day of issuing COA?
Ive been in the UK for nearly 6 years now, on au pair visa and now student, could I apply for PR?
Cheers