Alch doesn't have lvl 3 upgrade. I think? If you have the gree, blue and pink seals you have all of them.
As for the question, I think the bank and bazzar quests alternate one with the other so you have to complete one to get the other. I'm not entirely sure, though. The final bank quest is, I think, clearing out Shifting Passages, so once you complete that I think you should get the Hex ruins buyout quest or something along those lines.
And no, you're not taking too long, depends on the run.