ILR Application - Urgent query on absence from UK

[Sundar1181]

Hi
I am currently in Tier -1 and this expires in Jan 2014. I have been in the country since 2006 on work permit.

I am planning to apply for period between Apr 2008 - Mar2013 of which I had been in work permit until Dec 2008 and from there on in Tier -1.
Please find my absences details as well

Apr 2008 - Apr 2009 - 14 days

Apr 2009 - Apr 2010 - 177 days

Apr 2010 - Apr 2011 - 65 days

Apr 2011 - Apr 2012 - 22 days

Apr 2012 - Apr 2013 - 85 days

My query is
1. Do I need to submit evidence for my absence as I am on Tier 1 from Dec 2008 ?

2. How are the dates for this application calculated. If I am applying on 25th Apr will this be calculated from 24th Apr of 2008 or 25th Apr 2008

3. If I am traveling outside UK how are the travel dates considered ? Will this include travel dates for being outside country or full days outside the country because it may increase my days outside UK bringing it close to 180

4. Do I need letter from employer for all above absence as I am on Tier 1 and I am deputed from India to work here so ideally my assignment is in UK for above mentioned period.

Advance thanks for all the feedback on above queries.

Thanks
Sundar