Completely agree with your quest-racing mentality. I was my realms first to 90, I love questing, but I also love the race. You only get to do it once per expansion, that's not often - If I choose to go slowly, I opt out of the race. If I enter the race, I do NOT opt out of leveling slowly and reading my quest text (which I also enjoy), I have a million alts to level and do that, none of them can take part in the race.
I'm also loving the max level content, I was hesitant about the 1 week raid lockout - but I've found instead of being an elitist bastard when I hit max level and grinding the best gear I could, I spent my first few hours after getting a realm first, flying around slack-jawed exploring for the first time since classic / TBC. I could actually explore. Blizzard have done an amazing job on pandaria, I wasn't THAT into the pandaren thematics, but pandaria is gorgeous and full of so many tiny details and obscure classic-style fun stuff (named mobs that drop temporary mounts etc) - it's fantastic.
I just don't think we'll be seeing anymore Sha raids; the last panda emperor vanquished 6 Shas, and we have 6 we can kill already. And one of the Lorewalkers said, "If you want to know about Pandaria's future, always look to its past."
So that leaves tier 15 quite a mystery in my mind. Maybe more trolls?