No
If the coupons are for Gamestop then you can in fact go to Gamestop and use them. They will not however accept coupons from other stores.
Some do.
Yes, they do. I've paid them via check.
No. They accept credit/debt card or pay pal.
Gamestop / EB Games
Yes
Yes
All Credit cards
Yes, Gamestop will accept copies of Pokémon HeartGold as a trade-in without the Pokéwalker. See the Related Link below.
You can buy a strategy guide at Gamestop, Amazon, Certain Book Stores, and other places.
Yes. There is a strategy guide for black ops, you can buy them at GameStop for about $20.00.
No, GameStop will not accept any scuffed controllers. While they do accept used equipment, they will only accept equipment and games that are in great condition overall. On the other hand, you could sell a scuffed controller in an online auction, such as on eBay.