ILR - couple of questions

[Ess2013]

Hello,
First of all, thanks in advance for replying - much appreciated. I have a couple of questions and would really appreciate it if someone could reply:

BACKGROUND:
I received my Tier 1 General visa stamp for 3 years on 13 April 2010 (application date was 24 March 2010).
I entered the UK on 17 June 2010 and left on 10 July, and then moved here permanently on 09 October 2010.
I received a 2 year extension to my Tier 1 General visa on 13 April 2013.

QUESTION 1: When can I apply for my ILR, if my visa expires on 13 April 2015? I understand I can apply 28 days before 13 April 2015 (i.e. 16 March 2015). Is that correct?

QUESTION 2: In order to calculate continuous absence, it needs to be from the date of application, e.g. if I apply on 16 March 2015, I will calculate continuous absence from 16 March 2015, back to 16 March 2010 - I wasn't in the UK then, so how is it possible to calculate till that date? Does that mean I can't apply till around 24 March 2015?

QUESTION 3: I understand the 90 day consecutive absence rule has been removed - is that correct?

QUESTION 4: It seems there is a new 'Letter of Absence' requirement - is that for people who have exceeded 180 days in a calendar year or for everyone? Also, what about the times when you were looking for a job - how is that accounted for? I moved to the UK on 09 October 2010 and started my job on 10 April 2011. I then left that job on 20 July 2013 and started another one around 16 August 2013 (a contract position, which I left on 19 December 2013). I started a permanent job again on 7 February 2014. Do I need to contact all my employers and ask them to provide letters of absence? How will they be able to account for my weekend trips? This is really confusing!

Many thanks once again!

Ess

[Ess2013]

Any takers?

[Ess2013]

To add to the confusion:

When I was between jobs, I left the UK on holiday from 27 December 2013 till 21 January 2014 - since I wasn't officially 'employed', I can't provide evidence of being on annual leave. Is my passport stamp evidence enough? I read somewhere online that leaving the UK on holiday when unemployed breaks 'continuity', which sounds absolutely ludicrous! Can someone with proper knowledge of immigration laws please help?