We are talking about US law in this thread.
The alternatives that Tim speaks of is getting married in Ecuador instead of the DR. Some have married there but apparently the immigration process hasn't been complete yet so they have no results if the process out of that country works any faster.
Check it out
Dominicans to the USA
I do not understand your second question. If you are an American and married and you marry someone else I'm pretty certain that is called bigamy and is against the law.
