I am applying for an extension of my Tier 1 visa (initial one granted before April 2010). My application is quite straightforward, but I would just like to get some clarifications regarding the paperwork to be sent, since some it feels ambiguous to me
1) Date of entry to the UK (Questions D2-D4)
My situation : The question asks for entry clearance dates. I first came to the UK in 2001 under a student visa (to do my undergraduate), then again in 2004 under a different student visa (to do my masters). After that, I got a SEGS visa, then an employer sponsored work permit and finally a tier 1. I only applied for the student visas from India, but all the other visas were obtained while I was in the UK
My question: Which visa should I use here to show the entry date into the UK? Should I use the very first student visa, or the next one?
2) Earnings
My situation: I am aiming to claim payments from 01/02/2010 till 01/02/2011. During this period, my salary was raised, which puts me under a different band. However, during these dates, I have also received bonus from my company, which is clearly shown in the payslips.
My question: Should I simply total up all the money from the 12 payslips and claim for that, instead of the gross salary (since the salary changed in the middle of the last 12 months). Also, am I allowed to add the bonus into the earnings, or is it solely based on salary earned? The earnings band changes significantly for me based on inclusion/exclusion of bonus payments.
Thank you very much in advance for reading through my questions. I'll gladly repay for this information in the form of beer

Thanks
Kunal