As long as you are running 10.12.6, it's fine, but I think you'll get better result with latest 10.13.4.
There's a new file system APFS that might still be a bit glitchy, but you could still run it on HFS+
Yes, onboard ethernet or USB tether will be fine.
Only issue with this model is the lack of full touchpad support...there's development so stay tuned.
Not sure what you mean by "the grab background/black Apple logo and black background/white Apple logo screens"
Maybe post a screenshot here so there won't be any guessing.
Cheers