Currently I am on student dependent VISA (Tier 4) and I will be eligible for Tier 1 HSMP Visa in 1st week of March 2011, Now my question and confusion is -

1) Can I apply for Tier 1 HSMP Visa within UK or not? Because some people say I have to go back to my home country for entry clearance.
2) I came to UK in November 2009 and my Visa is valid till January 2012, as till date there is no certainty about PSW I want to apply for HSMP as I will qualify for the same - But if my Visa gets rejected can I apply as a PSW spouse dependent Visa ?
3) If my wife also apply as HSMP dependent (Tier 1) from her current status Student Visa (tier 4) – can she apply with me within UK?
And what are the impacts on applying PSW after her studies, if HSMP visa gets rejected.
Your efforts and reply will be deeply appreciated.