According to the Bronycon Q&A, Lauren basically wrote Discord as Q from the get go, and were going to use a sound-alike. They decided to spring for the real guy. So the request came from the MLP side of production
Maybe, although I think the episodes were pretty much in the can before S1 even aired, since they were part of the S1 production schedule. Hence the remastered theme song that won't appear until episode 3.
And Jayson claims they don't intentionally add stuff for bronies, all the stuff we pick up on are just things the writing crew and artists find amusing themselves