The key point is if you have a close friend in Canada

Then for 1, he can receive your maple card and mail it to you. You can open a bank account/apply a social insuance # with his address.

2. Don't say unnecessary words if they don't ask (even for your US prcess). Excessive words will always get you into trouble.

3. I renewed my H1 in vancouver back in 1997. If you have the supporting documents, it shouldn't be a problem.