Tier 2 General Visa Holder - Employment Options

[MagicMovies]

Hello,

My friend has a limited company in the UK and he is applying for a Tier 2 Sponsorship License. Once he receives it, he will be sponsoring my Tier 2 General Visa. Now, all of this is legal in the UK and I can travel to UK (assuming everything goes fine).

There are a lot of opportunities for my skill (BPM). My questions are -

1. Am I allowed to directly take up employment with company (client) which has work in BPM (not the same as my friend's company)? I am assuming that NO, because I can only work for my sponsor (my friend's company). Is this correct?

2. What sort of agreement should the sponsor enter with the client so that I can work for the client, the client pays money to the sponsor and the sponsor pays me my salary?

3. Assuming the above is feasible, can the agreement (as mentioned in 2) be allowed for contracting opportunities where the client pays a day rate for each day of work that I do - rather than fixed 2 year business deal between the client and sponsor. That is, my sponsor becomes a supplier to the client and he is delivering the requirements via me.

4. If I find a job (contracting opportunity which pays 300/day), what should my sponsor do in order for me to start working on that job?

Thanks in advance!