Exped Schnozzel is also a pack liner

Yeah the Schnozzle is brilliant.

It makes a very comfy pillow also.

Suppose it's storming when you make camp. Now all that stuff you want to keep dry has to come out when you inflate your mattress. Maybe that's ok, maybe not. There is something to be said for a dedicated pack liner.

I've tried to use the Schnozzle Bag as a pillow, but the roll closure always gets crazy contorted no matter how many times I roll it. All the same, I like the Exped Synmat UL 7 with the Schnozzle Bag a lot. I sleep warm and comfortably and don't pass out inflating it.

…

If for some reason the inside of my Snozzle got damp I would dry it with a pack cloth or a buff or something similar.
If it got ripped I would patch it there and then with Tenacious tape.

Even if it was slightly damp I would not worry much about it as there is often plenty of water vapour in the air.

I did a leak test on the Snozzle recently and its completely water tight except for the pump connection.

"Am I being dumb, it's OK. GO ahead and tell me."

I can't. I don't like being negative….

"But if the schnoozle gets wet, isn't there a chance of transmitting the moisture to the pad. Oh, are we talking about using the schnoozle with a downpad, right?"

Since the water is not going to go through the bag, just ensure you're storing your stuff inside the bag, the part that would also hold the air, so that doesn't get wet. The nozzle part is protected by snapping it into its mate when you're not using it.

"Also worried about a puncture which would prevent inflating the pad. Would that mean taking 2 schnoozles?"

As Stephen already said, just put some tape on the puncture and you're good to go, but I'd think the chance of a puncture is pretty low unless you're not paying attention when you pack.