Tier 2 ICT to Tier 2 General

[Ravilation]

Hi,

I have a tier 2 ICT (awarded Jan 2011, and renewed & valid till 31 Jan 2015). I am looking to migrate to a tier 2 general and have found a employer/ sponsor who is willing to do the RLMT/COS issuance etc. As i have come before April 2011, i can do an in country switch. However due to some personal issues/ commitments, I would ideally not like to start working for this employer till 1st of April. (i have not yet resigned from my current employer)

I understand that my new employer must issue the COS within six months of the Resident Labour Market Test adverts being placed
I also understand that i cannot apply for permission to enter/ stay more than 3 months before the date when I am due to start work.

I have the following queries, can you please help me with a response/ opinion.

1. Can I apply for my Tier 2 General Visa in Jan (say priority appointment) but have my employment start date as 1st April (I plan to be in India during this period)
2. if the above is possible, then are there any restrictions/ issues/ things one must be aware or take care of
3. if it is not possible, then assume that my new Tier 3 general visa must start no later than 1st feb 2015. However can I still officially start on 1st April 2015 - if so, does my employer need to pay me salary or the govt (NI) for Feb & Mar
4. am i correct in assuming, in both of the cases, my time spent in the UK for ILR considerations will be either the 1st of feb or 1st of Apr as people who have come into the UK on ICT post April 2010 dont qualify for ILR (unless they stay for 10 years)

Regards