Couple questions regarding ILR

Hi all.. couple questions regarding the ILR (set M) form hoping someone could clear up. this is regarding my wifes application

1. Booked a premium service centre appointment, £1900 paid by mum on her card (as a gift, wohoo!) and have printed out applicaiton payment sheet with barcodes on. The 08/15 Set M form I downloaded, has on the 4th page a 'Payment details' sheet which seems to need to be completed.

Do I need to complete this sheet including getting mother dearest to sign in the card details signature box.. or is this page replaced with the printed out sheet with the barcodes on given the premium appointment in person service?

2. Given the "duty to state all reasons to remain in the UK" statement at the bottom of the first page of the form I am a bit concerned we should be putting something in Section 8b which we have currently left blank? I mean other than signing the declaration at the end we havent actually mentioned any reasons in the form why the wife wishes to stay in the UK..!

Is there some standard bumpf we should be putting? I suppose it could not hurt to put something like "so we can have a family in the UK without fear of having to be separated for immigration reasons"?

Any advice welcomed