I have dual citizenship and how do I enter Canada to study in university

[ang]

I am 18 years old. I was born in US and my mother is a Canadian who becomes a US Citizen and we all live in US. My mother has dual citizenship with US passport and her CDN passport expires.  I already have a Canadian Citizenship card when I was 3 months old.  I am graduating from high school in USA and I get accepted to a university in Ontario.  When I applied the university, I applied as a Canadian Citizen.  Recently, I applied and received the Canadian Passport.  My parents will drive me from USA to Canada over the Labor Day weekend to go to University. I plan to stay for 5 years with my studies and co-op terms.  Then I will return to USA.  I learned from this forum about entering Canada using Canadian Passport and using USA Passport to return USA.  I have the following questions:

Is it legal to carry both US and CDN passports to travel between these 2 countries?

What is the legal age for being as an independent (ie. no guardian needed) in Canada?

When my parents and I drive thru the border, my parents will show their US passports and i will show my Canadian passport.  If the Canadian Immigration officer question me and how should I answer: Why are you using CDN passport and your mom is not using CDN passport?  Why are you entering Canada?  How long will you stay in Canada?  Will they deny me to enter Canada?

At the end of school year, when my family drive me back to USA going through the border and we will all show our US passports, will the US immigration officer ask us 'how long have you been staying in Canada?' For my parents, they will just say 1 week. For me, how do I answer this question?  If I tell the immigration office that I have both US and CDN passport, is this  legal in USA?

I will work this summer in US and I will report my income tax to INS in USA. I may work part-time job in university in Canada.  Since the total income for both jobs will most likely less than 10K, can my parents claim me as dependent? How do I report income tax in 2 countries? 

I will buy the university health insurance for 1 semester.  Should I apply the Ontario OHIP even though I never live in Ontario prior my arrival in Canada? 

If I show my passport to the university, should it prove that I am paying the CDN student fee? 

I will work co-op terms in Canada, what are the required documents to apply SIN card ?

Thank you in advance for any advice. 

[Leon]

It is legal to be a dual citizen and have two passports, both in the US and in Canada but you don't go around waving both of them at the same time though.  Your mother should also use her Canadian passport to enter Canada because she is also a dual citizen.  They can not deny you entry to Canada with a Canadian passport.

When you go back, you should use your US passport.  If you are asked how long you stayed in Canada, you tell the truth.  If they ask why you don't have any stamps in your US passport, you tell them that you are a dual citizen.  If they ask to see your Canadian passport, you can show it to them.

The age of majority in ON is 19 but I am not sure if it is a big problem if you are younger.

You should definitely apply for OHIP but you will not get it until you have lived in ON for 3 months.  I don't know what kind of health insurance your university is offering.  If it is complete health insurance for foreign students, it would be ok for you but if it is only supplementary insurance meant to be used along with OHIP, you should get travel insurance for your first 3 months in case you have an emergency.

As a US citizen, you must file taxes in the US regardless of where you make your money.  In Canada, you file when you are living in Canada.  The two of them have a tax treaty.  When you file your taxes in the US, report your Canadian income as foreign income.  I do not know if your parents can claim you as a dependent.  They should ask their tax advisor about that.

As soon as you come to Canada, you can go to Service Canada and apply for a SIN number.  You will get the number right away and the card in a couple of weeks.  You shouldn't give it out to people unless it is absolutely necessary.

[ang]

As a US citizen, you must file taxes in the US regardless of where you make your money.  In Canada, you file when you are living in Canada.  The two of them have a tax treaty.  When you file your taxes in the US, report your Canadian income as foreign income.  I do not know if your parents can claim you as a dependent.  They should ask their tax advisor about that.

For my case, I will work this summer in USA only.  I will be back with my family in USA by Dec 31.  Does it mean next April, I only need to file USA income tax?  Even though I live Canada for about 3.5 months, do not work in Canada during year 2011, have a Canadian bank account with minimal interest, receive my SIN card, and received OHIP, do I still need to file Canadian income tax?

I read somewhere that if I am a Canadian and have been living in Canada, when I leave Canada and work abroad in USA, I still have to file CDN income tax form unless I submit a non-resident form to avoid dual tax.  Is this true?

[steaky]

I think you need a cross border (Canada-US) tax expert to answer question like this.