19 Year Old Moving Back to Canada

[johnson1025]

I am a US citizen who married a Canadian citizen in 2003.  My wife has a son who moved to the US when we married.  Both have green cards.  My son is now 19 years old and is planning to move back to Montreal, where he intends to work and go to school. 

He is pretty sure he wants to stay there permanently but at this point in his life, he could easily change his mind a couple of years from now.

I would appreciate any information that anyone can share in regards to this process.  I've checked several websites but get confused.  Here is basically what I'm curious about most:

1.)  What steps does he need to take to get back into the Quebec educational system, and be treated as a Quebec resident (or Canadian citizen) for purposes of tuition, etc.  He's finishing one year of college in the US.
2.)  Does he automatically give up his US permanent residency?  If so, and he decides to return, what happens?
3.) How would he get access to healthcare as a citizen of Canada?

4.) Are there any options that he has regarding his status in either the US or Canada that are important to consider.

5.) What does he do regarding his taxes.  He had some interest income while in Canada and was paying taxes on that while he lived there, and paid taxes to the US during the time he was living in the US.  Does this cause problems.

Thanks in advance for everyone's help.

[Leon]

1) He moves to Quebec, registers for a college and shows them his Canadian passport.  As far as I know, it is as simple as that.

2) A green card holder may not be outside the US for more than a year without a returning resident permit but US immigration can also take a green card at any point the think that the green card holder has permanently moved to another country.  He will just have come visit you a lot and hope he gets away with it.

3) He would go to the health care office and tell them that he has just moved to Quebec from the US and he is a Canadian citizen.  He would have to wait for 3 months before he would get coverage.

4) His status in Canada as a citizen is not an issue.  His status with his green card could be a problem, see 2)

5) One of the things that US immigration uses to determine residency when deciding to take somebody's green card is if they are still filing taxes in the US so he should probably file in both countries.  They have a tax treaty so he shouldn't have to pay double.