For efficiency and profitability, most production units are 640 acres, but not always.
Yes, all mineral rights owners within the production unit, should be paid for their gas. Be aware, however, many land owners in WV do not own their mineral rights - often they were severed from the surface, generations ago.
Your deed should tell you if you own your mineral/gas rights - or surface only.
You will get royalties from every well in the production unit - based on the amount of acres you have in the production unit, and your royalty percentage is also shown on your lease.