Payment Officer-Would I be held liable?

I am a new mother and I posted my resume on job boards looking for positions that would allow me to work from home. I have recieved 3 offers from 3 different companies to be a "Payment Officer" for thier companies. What they require is someone in my country to recieve payments for thier companies, cash the checks or money orders, keep 7% for my pay and forward the remainder to them. They state the reasons they need this service is because they are located in China and it takes up to 1 month for a Canadian or US check to clear thier banks and the cost for their banks to do so is aroud 24% so it would be more cost effective this way.
What I need to know is, how to verify if they are scammers ie. if the checks are real, if the checks are from the account holder and not forged, how to verify the people writing the checks have recieved what they are paying for. Mostly, I need to know if I do cash the checks and keep my pay and forward the remainder, could I be held liable if it turns out that it is fraud?
They have assured me that it is completly legal and even signed a form I wrote up that states very clearly that if they are commiting fraud I will in no way be held liable and if the monies had to be repaid that it would be their responsibility to repay all monies including the 7% deducted for my services.

Please let me know if I can get in any trouble for doing this, I am desperate for money but need to cover my back.

It is a very common scam--the checks are eventually fraudulent and you will be held liable.

Confirm with the FBI if you wish...

yes you are liable we just lost $3000.00 the people are actually from Nigeria.

Sad to see this scam keeps going on, with new victims!

I answered a job ad also. They sent me 4500 to my bank account then a few days latr they asked for 90% of it back. So then a few days passed, and my bank called me and said I have been a victim of fraud and identity theft. Of course I have LifeLock; so the scammer can't get anything from me. I had already spent some of them money also. SO i called the bank where the money has come from; and they told me I will not be liable; as long as I filed a report with the F.B.I. Of course i did that so now I'm all in the clear.

Why are you worried have you broken any laws?
If not do not worry
If you have broken laws then you might want to worry.
This is real easy to figure out.