URGENT HELP REQUIRED -applying for a tier 2 visa

I am currently on a wk permit visa but i have been made redundant since may this year. i have a job where the employer has issued me wiv a liscence to apply for a tier 2 visa. now the employer wants me to start work asap before the tier 2 visa is issued. i am not sure whether i should do this... my offer letter actually states my start date as being two weeks from the date of my interview. will the home office not pick on this?
1. does the home office check with my previous employer if i'm still in employment there?
2. will they check randomly at my new place of employment if i start before my tier 2 visa comes
3. my previous employer has not informed the home office that i've been made redundant... does that give me a legal right to be in the uk since i can feign no knowledge of the 28 day rule. this is not stated in any of the documentation i received from the home office
4. finally anybody with any bright ideas how to make me feel better about this

You cannot start the new job until you have your leave to remain for Tier 2.

You are able to stay in the UK until your leave is curtailed, but don't breach your current conditions by working for another employer. If UKBA check it could be a 10K fine for the employer. Tell them to be patient.

They could also find out at a later date even if they do not find out now. Your new employer should not jeapardise their sponsor's licence.