Shaq did just fine with the Suns last season. You can run with your wings, and if the break doesn't work then you establish the low post with your big man. How much running do you think Kareem did with the Showtime Lakers later on in his career (not comparing Yao to Kareem, just saying you don't need your center to run on the break).

Nash has no problems running half court offense. I don't know too many guards who can pass and shoot lights out that do. He would be a perfect fit in Houston. It's just too bad we don't have enough assets to get him.
True. I mean, if there were some difficulty with Nash having to run more of a halfcourt offense in order to mesh with Shaq, we would have seen something like his numbers going down, or the Suns dropping from the ranks of the elite even before key players started getting injured.

Or, if Shaq were not kosher with an up-and-down running game, we'd know if, say, hypothetically, if the Suns were to panic midseason after the halfcourt experiment failed, fire their coach, and start running up and down the floor again, Shaq were to start complaining about it and muse about being traded.

But since neither of those things happened and the Suns turned in their usual strong 59-win season, that proves you are correct.