Mortgage & lodger consent form confusion

Hi all,

I have recently been looking into taking in a lodger into a spare room in my flat. I have informed my mortgage lender, who have approved, but they require a occupier consent form to be completed so that the lodger will not have rights to stay in the event that I move or get repossessed. I'm hoping that somebody out there will be able to help me decipher this form, because i can't make head or tail of it...

I've uploaded a copy of it here..

http ://i.imgur.com/fJIqArh.jpg (sorry, couldn't link as it's my first post. just remove the space after the http)

So my questions are..
1. In the first paragraph, it says "occupy the property after completion of the mortgage". I don't understand that. I've got in excess of 20 years to pay before I complete the mortgage. I also don't understand the entire sentence in bold. I would have thought Leeds BS was the mortgagee?

2. In the form fields it mentions "Borrowers" and "Advance Amount". What does this refer to? Is the lodger the borrower? There wouldn't be any borrowing going on between the lodger and myself. It also asks for the "application/account number". Would that be my mortgage account number? I'm not sure I'd be comfortable with my lodger knowing that account number. Call me paranoid, I guess.

3. These are mentioned again in the points further down too. It also has a "Name" field that I can't figure out if that would be a repeat of the lodgers name as would appear in the "Borrowers" field :-S

So all in all, I have no idea what anything on this form is about or what it's binding myself or the lodger to legally. Please can anyone that speaks financial legalese help translate it for me?

Thanks in advance!