yep. no divorce = still married.
She can't if she wants to stay in this country.
Technically yes. It is illegal to be married to two people (that is bigamy). And the fact that you have been legally separated, although a distinct legal status, means that you are STILL MARRIED. You are able to get engaged (because you are technically single) but you should be aware that being separated is not being divorced.
No!
The license is legal if the application was filled out properly. However, the issuing of a license will not change the status of the husband, he remains in the country illegally.
If not legally separated, you will probably have to wait until open enrollment through your employer to cancel her insurance. If you do get legally separated, you can cancel insurance as you have had "change in status." Usually insurance companies will process changes outside of open enrollment when you have a change in family status. An example of this would be getting married, having a baby, or getting divorced/legally separated.
Marital status refers to the legal relationship between individuals in terms of being married, single, divorced, separated, or widowed. It is a categorical measurement that identifies a person's current relationship status in terms of their marital commitments.
In the US, anyone can sue anyone for anything. The question is not whether you can sue, but whether you can win. Lying about marital status is not an actionable claim, and the mistress would not win.
If they are an adult their status is still the same, they are an illegal alien.
It is not possible as he will be deported because of his illegal status. Chance of his application to get approved are very thin as he will be banned for 10yrs (sometimes applicants can appeal against it under specific circumstances).
An alien is not illegal as long as she/he has documentation of status. An alien who is documented to be a permanent resident is not illegal. If the alien does not have and never has had documentation of an immigration status, then that person is an illegal alien.
If the immigrant married a US citizen, then that's a done deal and she is no longer illegal. It sounds like you need to take care of your own affairs, starting with divorce proceedings.
my status is single