I'm going to reply to each of these points so bear with me...

Quote Originally Posted by Tsuga View Post
Your plan limits people to selling things on retainers still, basically forcing us to use the limited capacity wards,
Yes, and so does the AH as implemented in XI in that only 7 items could be sold by a single player at any given time.

Quote Originally Posted by Tsuga View Post
and it relies on items being sent to mailboxes, a system that is not simple, or time efficient. This hurts the AH side.
You'd have the option to pick up the item immediately by warping to the retainer. Yes it requires a few more seconds. So?

Quote Originally Posted by Tsuga View Post
It also takes out pretty much any reason to go window shopping, because anybody with a brain (or without 30 minutes plus to try to find a few items) would use the buy it now function, thus negating the need for retainers in this system at all.
I agree, most people will buy from the menu but that doesn't mean that everyone will all the time. Options, it's about options.

Quote Originally Posted by Tsuga View Post
They would only serve to limit the sellers, and waste people's time by forcing us to set up the retainer in a ward, and go back and check it whenever we want money, or to exchange items with it.
Ok, so lets say SE separates item storage from buying and selling, but then we have to create a place to store items which you still have to go visit and give items to. No time saved either way in the end.

Quote Originally Posted by Tsuga View Post
This could all be handled by an auction house NPC instead, so the process of buying and selling would be streamlined. The Wards would just be there for anyone else who really wants to use them (or if there were items that could only be sold on characters/retainers, they'd be sold here, like XI's RBF).
I think i've addressed this, fix the search and allow people to buy from the menu. How much more streamlined can you get? The option for a time delay for receiving items bought in that way was a suggestion, not really one that I'm tied to for any particular reason, it's intended to create incentive to use the retainers. An alternative incentive would be a higher delivery fee.