Re: "We worked with partners to make sure their applications..."
I feel it would be remiss of me to not correct you regarding the the "quality control testers" you refer to in point b of your post.
Microsoft point out that they have millions of such testers who are independent of Microsoft and (in this case alone) do not receive any payment or funding from Microsoft so they are very impartial and not financially swayed. In fact quite the opposite is true, these people actually pay handsomely to Microsoft so that they may have the privilege of being involved in testing.
Microsoft do not disclose what title or position they class these testers as but I do believe that companies elsewhere refer to them as "customers" ;-)