If my employer requests me to sign company checks for him is there any way that I could be committing a crime?

If you mean that the employer is requiring you to sign his name for him, that is indeed risky. You would technically forging his name on the checks, and if he later disavows the signature--that is, he claims he never authorized you to sign the checks and never told you to sign his name--you could face civil or even criminal liabiltiy.

The correct way for  you to sign business checks is to either add you as an approved signatory to this account, or to set up some new (smaller?) account over which you'd have signing power; then you would sign under your own name.