Can i switch to tier 4 student

[SA2000]

Hello, I am a silent reader of this forum. I am tier 4 dependent . At the moment I am studying as a tire 4 dependent. My husband studying acca . I want to do masters .I will really appreciate if any one take some time and answer my questions.
1 . If I get level 7 cas from university can I apply in country?
2. If I have to go back to apply in my country and if visa refuse what will happen my current visa (valid until 15/02/15)
3. Please explain ( UKCISA)
Points Based System dependants

Points Based System dependants who apply for leave to remain in the UK on or after 1 October 2013 will be able to 'switch' into that category from other types of other immigration permission, though not from visitor leave, temporary admission or temporary release. This affects the dependants of Tier 1, Tier 2 and Tier 5 migrants. It also affects the dependants of Tier 4 migrants who are:
government-sponsored and studying a course over six months long
studying a postgraduate level course at least 12 months long and sponsored by a recognised body or a body in receipt of public funding as a higher education institution

It means, for example, that it will be possible to apply as a Tier 4 dependant after having been in the UK with Tier 4 or other types of leave, without having to leave the UK to apply for entry clearance. This is as a result of a judgment of the High Court.
Kind Regards