ILR

I am on Tier 1 (general) visa, before that I was on work permit. My 5 years of legal work period are going to be completed on 17 September 2012. I believe I can apply for an ILR 28 days before this date (around 20th August) and at that point my Tier 1 assessment will take place once again. While I will make up the required points, particularly those of earnings based on my consecutive 12 months earning in the past 15 months, I may not have a job in August 2012 as my main job is coming to an end in April 2012. My questions are:

1. Will they check whether I have a job at the time of making ILR application or they will just assess my case on the basis of 12 months of the past 15 months? Is there any sort of requirement of an employer letter confirming that I will continue working for them from then on? Does unavailability of such a letter, or not having a main job put me at a risk of rejection? I will have a part-time job at that time but my income from that job would be very small.

2. Can I cover the period from May 2011 to April 2012 when I apply for ILR around 20th August? Or it has to be June 2011 to May 2012? I basically need clarification on the idea of 'immediate 15 months'. The earnings are just on the margin but are comfortably met if I take the former period.

Many thanks
Dr Rizvi