sorry but my english is not good enough for this.
google traslation
With the semi-underground walls there is not option but drainage ditch
1. To dig around (if semi subterranea cava around the pair of walls that are under the ridge, if not therefore the side from where there are indications of streams to divert them),
2. retaining stone wall,
3. cover the trench so that it does not fill with snow (or your children fall) with ridiculously large and expensive slabs,
You may not have sufficient depth of foundation for the drainage ditch and that you touch deeper ... so much fun!
To us they have recommended that we do NOT happen to fill the stone walls whole (just the enought so that no rats live inside, not wind and those things) and that we do not use cement because its Capillarity is going to be terrible moisture.
Lift the entire floor of the interior and excavate at least 20cm to put pebbles and drainage underneath (ours is that it was never home but yours is surely better done and need not ...).
Mud plasters are supposed to be good for letting the walls breathe and for regulating indoor humidity (which will also be good not to subject too many expansions and compressions to the wood - the better wood that has grown in a similar climate, bring pine "Ecological" of Catalonia is to subject it to dilations until dangerous, so we have been told.
In the ceiling we thought to put cork, But many people are putting wool with borax, which is already a big improvement over traditional heather.
Go telling us how you are solving it! To us be able to use your knowledge ... any idea of solutions simpler / economical / diy NOS INTERESA
suerte
and fabaceas zone 9 (plus licorice!)
https://permies.com/t/62227/Nitrogen-Fixing-Species-Agroforestry-Systems
... i liked it, is eatable, after treatment; and good wood 
como mola! i want neighbour who do irn forge!!!