Are items crafted in World of Warcraft more useful to other players than crafted items typically are in other RPGs?
Throughout a player's career as a crafter, there are certain items that he or she can create which will be the best items at that level. For example, at level 40, the best bracers might come from a player with the blacksmith trade skill, while at level 45, the best bracers might be from a quest. There are also a number of consumable items that can be created by players with trade skills, such as armor patches and sharpening stones. These consumable items can be sold to other players, who can use them to improve their existing armor and items.

Can players use crafting professions to recreate the same item over and over as long as they get the right materials?
Yes.

How does the trading interface work?
You must be side-by-side with another player to trade. The interface is designed to be as secure as possible. A similar interface is used to provide a secure system for enchanting and unlocking boxes and so on. This prevents wow power leveling you from having to actually hand over your items to the enchanter, whom you might not fully trust. In World of Warcraft, the enchanter doesn't have to have physical possession of your item to enchant it.