H1B - OPT Issue

[Bittu]

Hi,

My H1b got denied due to wrong filing from employer, he requested the start date greater than 6 months as my OPT is valid till Feb-2013 and filed H1 on June 1st 2012.

He filed MTR now and yet no response from USCIS.

I have few questions now:

How long will USCIS take to approve the denied petition.

Do I need to reapply for another school to maintain status though my opt is valid till feb-2013, if I do so am I eligible for getting CPT after using my OPT.

If they approve the MTR after getting the CPT then what will be my H1 start date ideally it should begin from this December 1st 2012, will my status will change back to H1 from CPT or will that H1 will be cnacelled out completely?

Let me know.