>if X launches from Texas, is there a nice place to land the first stage?
I'm not 100% certain, but my understanding is that the plan is to, depending on the amount of extra fuel allowed by unused payload capacity, either fly directly back to the launch pad, or land on the floating barge to refuel and *then* fly itself back to the launch pad. Though I remember some talk about SpaceX leasing one of the more remote and durable launch sites at Cape Canaveral, Florida, so I imagine they plan to eventually land there for refueling rather than on a barge in the open ocean, with the associated much greater weather sensitivity.
It may seem kind of wasteful in terms of both fuel use and engine wear and tear (though I believe only one of the nine engines is used on the return flight), but consider that the first stage is about 45m tall (around 15 storeys), with an empty mass of about 25,000kg (approximately the maximum mass of a loaded 20-ft shipping container). The size means it's pretty much impossible to transport over normal roads, and the mass means that only the largest military cargo helicopters could handle it. And I would assume it's not designed to survive significant lateral stresses (no point in normal usage = wasted mass on structural supports = reduced payload), so laying it on its side to transport it by ship or truck would probably be a major challenge. So either you build and maintain a specialized transportation vehicle, or you just let the thing do what it was designed for and fly itself.
>How far downrange was the barge, and what is that far from TX.
I've heard 400km, though I couldn't give you a reliable source. And obviously that's fairly trivial to extend considering the first stage is already hurtling downrange at high speed when the second stage separates. If it simply "glided" down to to cruising speed, just maintaining high altitude (low air resistance) instead of actively decelerating, it could extend that range considerably while likely consuming even less fuel (obviously the fuel required for the return trip would increase, but that has no effect on payload capacity).