A) Auction House feature IS NOT with the intentions of hurting or benefitting merchants, it is simply to make trading easier for players, which in turn makes merchanting easier but a little trickier as well. That being said the effect it may or may not have on merchanting SHOULD NOT have an effect on if it is implemented or not. I played OnC for a couple weeks, mainly merchanting with their auction house and I was able to make thousands of gold extremely easily.Merching is fine the way it is, this would only make it harder trust me. And farming bosses for 10m, thatd be hard, real hard, just saying. I would say how much i made from merching but i don't like bragging.Because it's just as easy/better if you know how to do it right... 10m a year really isn't that much either. I could easily make that farming bosses and stuff if I really tried.Y learn another way when I'm making 10mil+ a year and so r other top merchants
B) Clearly you don't farm bosses/mobs often because 10m+ a year from farming is relatively easy. 50k a day gets you about over 18M, 30k a day is a bit over 10M and there's been days I've been able to make 100k a day. Money bosses have a 15-30min spawn time and there are 14 of them in Carrow alone, you'd only need to kill about 4-7 to make 50k which isn't a lot especially if that's all you're doing and not checking other bosses.
Try playing another game or talking to others who have played games with auction houses/exchanges in the game, I will guarantee you that they would say you can still merchant just fine. More people buying and more people selling, sometimes players want to make money faster so they'll sell items cheap, or they're uneducated of prices and they'll sell cheap that way as well. You buy those items and then sell the items for the most you can get, little to no difference as long as you're patient and active with the market which is what being a merchant is about.