applied H1 this year(still waiting for receipt/rejection) want to apply for F1 visa

I am on H4 visa and have applied for H1 in April 2014. I have not heard back anything yet from my employer. They dont have any information on my status from USCIS. I have got admission offer letter from a University. I am planning to apply and study on F1 visa as I can get CPT/OPT later and I can work.

Can I apply for F1 student visa now ? 


If in the meanwhile, I get my H1 news from my employer that it got selected in lottery than what should I do? 


Can I cancel my F1 visa if my H1 get approved or can

 I stay on 2 visas at same time in USA.


I want to know which visa will be valid in this scenario?