It depends on the store I have seen where some would do it and others not just check your local store
Yes or it can be purchased as one single
I would say if it’s only 29” you should have a problem doing that at all. I think it would look just fine.
I can do 20 sheets on a 1 ton without trouble
I bought mine individually however the bundle option was available
Price is per sheet.
currently 8.93 per sheet and can be bought individually. They are packaged in twos. buy 34 or more and price is discounted.
Not much: https://www.hyphensolutions.com/info/blog/r-value-of-drywall-will-drywall-help-insulate/
White
I would not