Can a tourist file for divorce in US after completing residency and not declare minor children in the petition? Will there be issues with this?

Your timing is excellent.  Just a couple weeks ago, I won a case in the Nevada Supreme Court (Senjab), holding that only 6 weeks' residence, not "domicile," is required to file for divorce in Nevada.  And while I woiuld want to know more about the facts before giving a certain answer, if Nevada is not the Home State of the children under the UCCJEA, then the divorce here would not address their custody.  See the article "The Basics of Family Law Jurisdiction" posted here.  Obviously, there are more questions to ask; I suggest that you call the office during regular business hours and go over the basic facts with one of our attorneys.