Switching from Tier 1 PSW to dependent of Tier 4 Student

[waqiikhan]

I am currently on PSW visa. My visa will expire in March 2014. I have planned to apply student visa of my wife. She is in Pakistan at the moment. I will go back to Pakistan in January and will apply student visa for her and dependent visa for myself on her behalf. I want to know that can they refuse my visa on the basis that i am planning to go for 10 years permanent residence as i already have around 5 and half years in UK, or can they refuse on any other ground??

My 2nd question is if i will apply in January, do i need to come back in UK before my current visa expire in order to be able to apply for permanent residence when the time period is complete. if my visa expires before coming back to UK can this be a problem in permanent residence??

I would be grateful if someone can suggest me in this matter. Thank you.