wanting to move back to quebec

Hi, I am planning on moving back to Quebec after 22 yrs living in the us, I was born in Quebec and now am a dual citizen. My plan is to continue to work here in the states but have an apartment in Montreal and commute. I also own a home here in the states which I am renting out, so I am wondering how my income taxes will be affected, do I file in the states only or do I have to file in both countries? 2 other questions I have is regarding my vehicle, if I can just keep it registered in New York or do I have to change everything over to Quebec and if I do, I know I will have to pay some kind of tax on it,even though I still owe on it, it's a 2010 vehicle. Lastly, I have a 21 yr old son who may come with me, I read somewhere that it is his birthright due to me being born in Canada to become a Canadian citizen, I wonder if this is true? He has had a couple misdeamenors with the law, and I'd like to know if that will be a problem, he is not on probation or anything, just has alot of fines. Thanks in advance for any and all info. Liliane