Re-entering Canada on H1 visa

I´m on H1 - did my landing in Canada last year, got the GC and SSN # & returned to USA.
Now I want to visit Canada for two days and meet couple of potential employers that I have spoken with, so I seek your advice on following;

1. If I drive into Canada - can I just show the GC to the officer at the booth and drive-on, or do I still need to get down and show credentials at the office.

2. If I fly into Canada - do I need to give my I-94 to the airline just as I would have if I was traveling out of USA to my country!

For returning to USA

1. Last time when I returned from Canada - the return was smooth, The US Immigration officer asked for my passport, I-797 and that was it. Has anything in the rules changed that should make me rethink or take any precautions! My H1 is valid till October

2. When I fly back from Canada - what does the US airline or Canada officials look for.
When I enter US airport (most likely at New Jersey) what should I expect - is it just like returning from any other country and get new I-94 or is it something different.
Many thanks for your help/feedback