Could I face criminal charges for receiving unemployment benefits while working another job

Yes, you could face charges of fraud if you fail to report income or conceal income in order to continue receiving unemployment benefits while working another job.

I'm not familiar with NC unemployment forms, as I am not licensed and do not practice in NC, but there should be some pretty clear statements to that effect on evey document that you submit in order to receive UC benefits.

If you properly reported the employment and the income and continue to receive UC benefits, then you should be clear, as the decision to continue your benefits was made by the Unemployment Compensation division after full disclosure by you.

Yes, you can, since working another job --being employed-- makes you ineligible for unemployment benefits. You've got to be unemployed to be eligible.

Lying about being employed so that you can still get unemployment benefits isn't a good idea, either. See NC Employment Security Commission Regulation No. 20.14: Any party who knowingly makes a false statement or knowingly fails to disclose a material fact in connection with the payment of benefits is subject to criminal prosecution for a misdemeanor as well as penalties imposed by the Commission. Any person receiving benefits to which they were not entitled:

(A) shall be liable to have such sum deducted from future benefits payable to him/her or to repay the Commission a sum equal to the amount received by him/her;
(B) shall not be entitled to receive benefits for one (1) year if the overpayment is found to have been made because of fraud.