This thread is more about synthesis as it relates to repairing items, not crafting as a whole.
Right now repairing items is very bothersome, as you either have to level a craft yourself or have to use the marketplace or the shout function to seek repairs. I think that this feature could and should be improved considerably with few adjustments.
What I am talking about are Repair Kits. The system could work as such:
New recipes involving items needed to repair items currently are implemented. By using these recipes crafters can create Repair Kits that can be sold to other players. With these kits, players can repair their equipment whereever they go by simply using the kit in question. To make buying and selling these kits less of a hassle, each item should not be given it's own kit but they should be more general in nature and specific to each craft, to avoid overlapping. So instead of there being a separate repair kit available to fix "bronze sword" for rank 4, there should be a repair kit to fix every equipment that uses smithing as the base for ranks 1 through 10. Then another kit for 11-20, 21-30 and so on.
Few flaws come to mind with this system, that can be easily avoided however. One, if the system was implemented like this it would take a lot of inventory space. Instead of simply raising the inv. space (which is possible of course), bags could be introduced that can hold every repair kit while only taking one inventory space total. These bags could be used for other items as well, such as ores (of all qualities) and other items that can take a lot of space. Two, it doesn't do much about fixing the in-game economy (aside from the tax for selling the items in the Marketplace) but as a good side crafters can see the results of their effort almost as transparently as before.
Like this, the crafting focus can be kept within the system while making the system much more convenient to use. It is certainly not the only way to 'fix' repairing, but I think it works.
EDIT: Wrong forum, feel free to move it.