Tax efficient plan for holding investments during a US to Canada move (US Citizens)

[dgroyal]

Hello. My wife and I are likely moving to Canada in the next year. We are both US citizens and will be moving as permanent residents.

We have a variety of investment accounts, and I want to make sure I handle everything as best I can in terms of avoiding tax penalties.

Current accounts:
Vanguard 403b
Vanguard Roth IRA
Vanguard taxable
Fidelity 403b
Fidelity Roth IRA
TIAA 403b
Nationwide 457

My current plan is to consolidate the 403bs (as a traditional IRA) at TD Ameritrade, roll the Roth IRAs to TD Ameritrade, and keep the 457 at Nationwide.

1) In reading through various forums, a lot of people recommend Schwab for expat US citizens. Are there advantages to Schwab vs TD Ameritrade? I picked TD because we'll likely use them for banking and they seem familiar with cross-border issues.
2) Can anyone point me to anything definitive re: the CRA's opinion on 457s? I'd like to just hold them where they are, because if I roll them into a tIRA we'll end up with an age restriction. Nationwide has said they're OK with a non-resident US citizen keeping an account open.
3) Where should I move our taxable investments to? TD says they can't do it? Maybe this is a reason to go with Schwab for everything...