No.
There is no law that requires you to notify your employer that you have filed bankruptcy. It is a public record, though, so it will show up on a background check.
Not that I am aware of - although you may check with your state Department of Labor to determine if there are any state laws regarding this.
the old cheque would have been invalid after 6 months, so you need to contact the person who issued you the cheque in the first place, however, they are not obligated to give you a new one, if they do, consider yourself lucky, however, I doubt that they will issue you a new cheque.
can my employer withhold my final check
Yes, perfectly legal. They are not obligated to pay your tax for you, but this is commonly done under a PAYE system.
I guess Yes. Banks are the only place you can cash a check. Since it is your paycheck from the job, the check will be from a bank account of your employer. So to cash it you either need to visit a bank that you have an account or visit the bank that issued the check to get the cash from the check.
A DBS check is a type of criminal records check issued by the Disclosure and Barring Service in the UK. DBS checks provide certain criminal record and police information about a job applicant that can assist an employer to make a safer recruitment decision.
An employer can do a background check for the past 15 years
Per Michigan state statutes 408.474 and 408.475 your final paycheck must be issued on the next regularly scheduled payday.
You can try calling your bank and ask them to stop the check immediately. If your bank has not yet processed the payment for the check, then the bank will be able to stop the transaction. However, if they have already passed on the payment to the target bank, unfortunately they cant help you because you issued the check and failed to notify the bank on time to stop the payment.
An employer can check validity of a driver's license by calling the DMV. They can also check its validity by looking at the expiration date.
For you as the employer? That would depend on the amount of information you are seeking.