As for evidence that the phase cloak can't just automatically phase trough everything:
Pegasus wrote:RIKER: The cloak appears to be functioning normally. The ship's matter/energy phasing rate should be sufficient to pass through the asteroid.
Destructionator is probably going to whine that i just copy from Mike, but who cares? I am just using his database to get dialogue.
Anyway, the quote above says that they have a "phasing rate", and that it is "sufficient" to pass trough the asteroid.
Now, that implies that they just don't "phase", and that it's either on or off.
Furthermore, the "rate" could be related to three things:
-the amount of material they need to pass trough. However, that appears to be unlikely, since they should speak about "capacity" or the like, not about a rate.
-the speed with which they can pass trough matter. However, that is unlikely, since they could just take their time, and they are not talking about speed.
-The density of the material they need to pass trough. This makes more sense than both explanations, and also fits with the statement about the asteroid.
So, let's explore the third explanation. It actually makes sense that it is more difficult to pass trough dense materials - you have fewer "gaps" trough which you can squeeze your own matter. If we use that mechanism (that "phasing" means that you squeeze your atoms trough the empty space in matter), then it's also easier to phase a less-dense material trough something - it would be easier to get flesh trough metal than to get metal trough metal. If that is actually the case, then the capabiltiy of humans to pass trough walls does not necessarily imply that a starship could pass trough the same walls.
Basically, this means that the maximum we see a starship-hull pass trough (assuming that it is the most dense part of the ship) is rock. The maximum we saw less-dense human being pass trough is a starship hull.
We can not conclude that a starship-hull would be able to pass trough another starship-hull.
If we use that explanation, then the amount of material they have to pass trough might not matter, they just need to contain a continuous rate. However, the generator might be under continuous stress while passing trough a dense material, since it needs to work at higher capacity. We don't know it's limits either way, but a limit of some kind would fit with the quote above.
Even if we disregard my entire explanation, we still do not know which "phasing rate" they can achieve, and whether or not it would be sufficient to pass trough the Deathstars hull. Given that the incident where humans were phased was based on an accident, we can not conclude that they are similar - that incident might have had a higher phasing rate.