I call BS.
+ The game didn't launch with RMAH at all.
+ The basic gameplay is exactly the same as Diablo 2. Tweaked mechanics does not mean a game is designed around an auction house.
+ People still sold items on ebay with Diablo 2
+ The entire game does not force me to go the RMAH even ONCE. I can play the game without even using the Auction House.
+ I can use the regular auction house if I want and not spend money
+ The regular auction house has no built in limitations that the RMAH is free of. they function the exact same way, but RMAH uses...real money...
If you are going to make a ludicrous statement that Diablo 3 was designed around RMAH, you better prove to me that I literally can't play or beat the game unless I buy or sell something on the RMAH.
Otherwise you are just being a fanboy excusing Valve, but attacking Blizzard. F2P or not, Blizzard gives you the option of choosing what type of Auction House you want to explore, and even gives you the option of completely IGNORING the Auction House.
All the design decisions for the way things are done in the game are designed around the RMAH, it doesn't mean that you can not play the game without using the RMAH because you can, but Blizzard made decisions with the game to make the RMAH as appealing as they can.
Lets see some examples of decisions that are the result of RMAH.
Always on DRM for single player. Sure they say they did it to stop cheating and I'd imagine in some tiny part they believe that. But it is obvious they wanted to stop duping of items because otherwise they would have no value and people either wouldn't buy them for real money or would pay pennies.
You are incredibly lucky to be upgrading your gear often with stuff you find while playing by yourself. In Diablo 2 (and many other clones) you would get new sometimes upgrading a piece a couple of times a level and usually not going more then 2-3 levels without finding an upgrading for a particular item. In D3 with all the characters I played (and people I know) I routinely had items that were 10-15 levels below my current level because they game didn't drop shit that was worthwhile.
Rare stuff isn't bound to you anymore so they it can be sold over and over and over.
I'm not going to bother getting into it anymore because frankly I don't care. If you can't see or at least understand how a lot of design decisions are/were centered around the use of the RMAH they forget it.
As for your points, true the game didn't launch with the RMAH, but considering how shitty the AH was in general at launch it doesn't surprise me that it was use to iron out some bugs before it launch shortly afterwards. Basic gameplay sure hasn't changed, mash buttons to execute spells/moves, the gameplay isn't the issue. People sold shit on ebay for nearly any game that was a competitive player base and guess what people still use chinese sites for D3 as well because they can still get it cheaper when cutting Blizzards cut out from it. You don't need to be forced to use something for it to be effects on the game design still.