Canada Landing while 485 Pending

I have 485 pending and have used AP. Plan to land Canada this month. I have some questions:

1. Does anybody konw it's better to fly to Canada and come back with AP, or go to Canada by driving through the border? I know some people had problem coming back to US because they have 485 pending and also landed in Canada.

2. Is there any bad effect in Canada if I fly back to US in a couple of days after the landing?

3. Can I still use valid I-94 with an expired H1 visa back to US if I fly to Canada but drive back through the border?

Thank in advance for any suggestion