HSMP MBA PhD and work Permit

Hi all,
My situtation is quite weird. I am a PhD (Cambridge) and working as a scientist in Oxford Univ on work permit valid till june 2007. I would have completed 4years on WP in Aug 06 and applied for ILR. I also planned to do an MBA at Oxford in Oct 2006 for which I am selected and paid the fees. Now, with the new rule from 03 April 06, my situtation is quite weird. I am thinking of applying HSMP now (which will supersede my WP) that I will get for 2 years. I am thinking I will go for the MBA for one year in October 06. When do I get the tax return for the period I worked at the Oxford University. Is it in April 06? I will be back to job in Oct 07 after I would have finished MBA. So again I will have some job till the end of HSMP.
1. Will I have any problem in renewing my HSMP at that stage?
2. Will I be able to apply for ILR while student in Aug 07?
3. If I decide to wait for 3 months more ie instead of applying for ILR just after 5 years, I apply for it after 5 years 5 months (when I will have job post MBA)?

Is it the right course of action? I wonder how HSMP renewal or ILR are affected if I don't work for one year period in a 2 year HSMP? Needless to say, I won't be taking support from the public fund?

Thanks for your help.
S[/u]