re: Deep ice below dry soil
I still don't get it nick. If theres water vapour pasiing through the regolith some of it ought to be adhering to the surfaces of soil particles. It's debateble whether these monolayers of water molecules could be classed as 'water' but they should be there, and the TECP should be able to detect them.
If the soil is utterly free of water molecules then there must be something hydrophopic coating the soil particles, which one of the other experiments should show us.
And if not, well I haven't got another idea, anyone else?