I don't think Crawford is untouchable if you're trading for a controllable CF. Nor Rojas for that matter. I just don't know that Robert is the guy, or if there's anyone else (including a full-time LF who would push Marsh to CF) at that level available. Those tend to be off-season deals.
Painter's just really good. There's no reason to think he won't make it back unless he gets hurt again. He's neither Abel nor Mark Appel, yet. If he disappoints he's still probably a ML pitcher.
Now, he might still get traded if the Phillies' rotation is set for several years to come. That would mean extending Ranger and not only keeping but actually pitching Walker. But since neither neither of those two things are certain, he should still be untouchable in addition to the fact that you'd be selling low.