I got the TN Visa... so what now?

I've been working on a TN Visa since Nov of 06. Everything is still so confusing for me.
1. I don't know what my Canadian residency status needs to be, nor what my status in the US is. If a TN Visa is only a temp work visa, and I am not even a temp resident of the US, do I have to remain a Canadian citizen?
2. Where do I file my income tax?
3. When I applied for a US driver's license, in South Dakota, they took my Ontario license. Will this cause me grief if I need to maintain a deemed-residency status with Canada?
4. I have kept all my Canadian bank accounts and RRSP/Mutual funds accounts. Can I have a Vanguard fund? Can I keep putting money away in my RRSP?

1. I don't know what my Canadian residency status needs to be, nor what my status in the US is. If a TN Visa is only a temp work visa, and I am not even a temp resident of the US, do I have to remain a Canadian citizen?
Your Canadian residency status is 'non-resident' your status in the US is TN. Yes, you remain a Canadian citizen unless or until you renounce citizenship. As you do not have eligibility to apply for citizenship in the US, you will not be renouncing your Canadian citizenship.

2. Where do I file my income tax?
Both Countries.

3. When I applied for a US driver's license, in South Dakota, they took my Ontario license. Will this cause me grief if I need to maintain a deemed-residency status with Canada?
It shouldn't no. Not with all your financial ties.

4. I have kept all my Canadian bank accounts and RRSP/Mutual funds accounts. Can I have a Vanguard fund? Can I keep putting money away in my RRSP?
I dunno what a Vanguard fund is, but yes, you can keep putting money in your RRSP until the day you retire.

Oops, on the 1st question, I meant to say lose my residency, not my citizenship. It appear the residency status' are:
a) resident;
b) factual resident;
c) deemed non resident; and
d) plain old non resident.

Don't you have to be resident of a country somewhere? And, I thought I needed to keep my residency to maintain my TN visa since, they want to know I'll be returning to Canada and not try to make this situation in the States a permanent one.

To be clear, when I file my US return, my status here is TN.

Does there need to be a link between my US declaration and the one I make in Canada? Since in the US I'll file with the US SSN, but in Canada I'll file with my Canadian SIN.

Thank!

On the tax issue, you have to file a 1040NR, when you get a SSN the SSA will give the address you give them to the IRS, and in theory the IRS will send you a 1040NR at tax time, but they never did for me. File Form 8822 to make sure they're aware of your address, or simply get a 1040NR from the IRS office and put your address on it at tax time.

For tax purposes, you're far better off moving your tax residency to the US if you can. You can file Form 8840, which says essentially you want to remain a Canadian resident for tax purposes, however tax rates in the US are lower. However, if you emigrate (for tax purposes) there is a CRA rule that they then assess you for an "exit tax", which is how Canada stops people from permanently moving to the US. I can't remember exactly how it is calculated, it's based on your net worth at the time you left, you need to get an accountant really to check in to the best of way of structuring your tax situation.

It depends also on how long you plan on staying in the US.

Bear in mind that immigration and tax are totally separate. The US doesn't give a damn what your immigration status is, nor does the CRA, all they care about is whether you meet their standard for tax purposes.

Wow, thanks Steve. Sounds complicated!