Well it depends.... The game is pretty straight forward and easy to finish BUT... The story is weak and characters are bland. IMHO what is good about XII is the hunts, sidequests and gameplay. So you will be missing the best part.

Sidequests: There are only two little sidequests that you need to complete the game: making a sunstone (first 5 hours) and the "pine chops" quest in Archades (middle of the game)

Hunts: You only need to do one hunt: The Rogue Tomato (first hunt). All others are optional

Selling Loot: Nothing that you sell will prevent you from completing the game. Keep only teleport stones. They are pretty handy.

Bear in mind that by not doing hunts, not doing sidequests and selling all loot you will miss the best weapons and armor in the game and quite a few Aeons (Espers). And barely enjoy what people like most in XII: The hunts.