ILR Dilemma, can this problem be solved?

Hi there

I have a query hope you guys can help.

Background:
1. Arrived UK on 28 Sept 2002, on student visa
2. Graduated from uni in 2008, got a postgraduate doctor visa (called permit-free training at that time) until Sept 2012.
3. Applied for Tier 1 early once I qualified for it, so currently I am on Tier 1 from 9 Sept 2009 - 9 Sept 2012.
4. Currently got a job contract with NHS until July 2015.

As you can see, I will be in the country for 10 years exactly on 28 Sept 2012. Unfortunately my visa ends several weeks before that. But of course there is the 28-day window which allows me some time to apply for ILR.

(Aim: To get ILR based on 10-year residency.)

Problems:
1. Not sure how long I left the country for holidays from 28 Sept 2002 until now. I have tried to check my passports, but everything is in a mess. I tried to do it systematically, but I noticed on some occasions my passport was not stamped ie when I travelled to Republic of Ireland and returned to UK. Please note, I WANT to accurately check when I left and entered the country, is there another way I can go about this problem and check how many days I have been away from the country so far? Does UKBA have these records ie is it in the SAR? By knowing this info, at least I can gauge how many more days I can leave the country for vacation etc until my 10-year anniversary.

2. There might be a slim chance my ILR application may be rejected, of course I don't want this to happen. I plan to apply for ILR as soon as I reach the 28-day window of course but I'm not sure whether you can apply in person anymore. If my visa gets rejected, what happens then? This leads to my following dilemma...

3. Should I just apply for Tier 1 extension in March 2011, just before they scrape the whole Tier 1 (General) on Apr 2011 to save the hassle and give myself some time? That would mean paying another £1K just to by myself around 6 months (because I am applying way before my current Tier 1 expires, and the extension is only for 2 yrs).

4. Worst case scenario, just not rush with Tier 1, apply for Tier 2/sponsored work permit maybe about 6 months before my Tier 1 visa expires just in case my ILR gets rejected. But is it necessary?

Ok sorry for the long questions, but I hope someone experience can show me some light!

Love always
Dupuytren