Tier 2 ICT to ILR

[har_p3]

I got my first CoS issued on 07/04/2010 and the CoS start date was that of 24/04/2010. I did enter the country for the first time on Business visa on 28 /02/2010 and left in 4 weeks to come back in May (12/05/2010) on work permit. The start date of business visa was 14/12/2009.
I never tried to apply for ILR at the end of 5 years as was not sure. Now, I will be finishing 10 years in few months. I have two main questions;

Am I really eligible for ILR on 5 year route (I know its a bit late now for that but none the less would like to know)?

If I go for ten year route, which is the earliest date I can apply for ILR considering all different dates above and different visa types?

Apologies for throwing so many dates around but was hoping if I could get some answers from experts here.

[CR001]

Am I really eligible for ILR on 5 year route (I know its a bit late now for that but none the less would like to know)?

No you cannot apply for ILR based on 5 years ICT as ICT visas issued on or after 6th April 2010 do NOT lead to ILR.

If I go for ten year route, which is the earliest date I can apply for ILR considering all different dates above and different visa types?

No sooner than within 28 days before the 10th anniversary of the date you entered the UK on your business visit visa, i.e. 28th Feb 2020 minus 28 days.

Presumably for ILR based on 10 years long residence, you meet the 540 days absence and have no single absence of 180 days or more at any time??