I believe more of those cards are dropped than crafted. But yes you can craft some blades and traps and sell them to the bazaar, depends on your school. But not too much of profit in selling treasure cards.
Not only do the trees sell treasure cards recipes, but with the release of celestia Avery Templeton in Base Camp and Kimba Kalla in the floating land also sell astral, myth and balance treasure card recipes that anyone can craft. They only need to meet the required crafting level.
The balance crafting students can craft blades and traps , storm also has storm trap that can be crafted , plus death, myth and life also have traps that can be crafted. The crafted traps are usually a little better, which mean they are different from the original spell and can be stacked on top of the original. The percentage of each of these spells I do not know off hand.
Balance Wizards are able to craft triple blades and traps, but rarely ever do. The cards you see at the Bazaar are drops from bosses or obtained from buying the treasure card packs available in the Crown Shop.
Treasure card versions of Spirit Blade, Spirit Trap, Element Blade, Element Trap, Tough, and Accurate are available at the the Library. The blades are pretty expensive, but can come in handy at level 28, 48, and 58 solo quests. Not sure what Balance does.