I prefer
Vendorizer for reagent buying, myself. It can also be used for auto-selling grays, but I'm using
Automaton for that. Automaton also does a lot of other neat things, not specifically related to optimizing the leveling process. It's really out of date, but since I'm still using it myself, obviously it still works.
VendorBait to know which quest reward sells for the most money, however I've not come across anything that automatically picks a quest reward and actually finishes the quest -- this only puts a highlight around the reward that will vendor for the most.
I'm using
QuestGuru for my quest log and tracker replacement. That may be a little more than you were looking for, but it *does* autocomplete the quests that don't require me to choose a quest reward.
I found
one addon that sounds like it did what you wanted as far as auto-mailing greens to your enchanter, but sounds like it's broken and abandoned now. Too bad.
My solution is to (a) use an inventory mod to make it easy to find my BoE gear, and then (b) just mail it manually. Since the inventory mod groups them all together for me and keeps them seperate from my soulbound gear, it's a piece of cake to do manually.
I'm using
ArkInventory for the purpose described above. It's the most powerful inventory management mod out there, but ... kind of a beast to get set up in a nice usable fashion. I could send you my savedvariables file for it, if you'd like to try it out with the default profile that I've spent years refining, and that I use for all my characters regardless of their class or professions. Or, the other inventory mod that I don't use but like recommending to people because it's so dead simple and still pretty powerful is
Combuctor.
Good luck, let me know if there's anything else I can help you with.