As long as they fit, no problem!
Not sure about that - we stayed in a cabin. I found staff there to be very friendly and responsive. I'd just call and ask.
It looked like a few people had more than one but I would ask them to be certain.
There were two tents at some sites, but unsure how they charge. This KOA does not charge for children 17 and under.
I am not sure, you might want to check with owners.
I don't know - we were in an RV.
Get an answer from West Glacier KOA staff and past guests.