[Strawbale] Tile on clay plaster/cob

[Orion Walker]

Hi folks,

Your advise on my questions below would be greatly appreciated:

My wife and I are now moved in to the upstairs of our beautiful little
strawbale and cob house that we have building over the last few years.

People keep asking me when we will be done, and I have to explain to them,
that building a house is not the kind of project that you ever really
finish.

Lately I've been working on some nice cob details on the inside, and doing
finish plastering on the inside as well.

I recently received a whole bunch of really nice tile for free, so I'm
looking for advise on how to use it in the house.

3 questions:

How should I go about doing decorative tile on the walls.  In most places my
base coat of earthen plaster is now fully dry, awaiting a finish coat of
either clay/alis or lime.  Not sure sure the best way to attach to the wall,
interface with finish coat, use regular grout, or finish coat as grout, etc.

I currently have a 3 1/2 inch thick earthen floor base coat on the ground.
I would like to do tile on top of this in at least some rooms/areas.  What
do people recommend as the best way to lay tile on an earthen floor to
attain adhesion and minimize cracking?

In the bathroom I am trying to figure out the best way to do a shower/bath.
Being that the walls are strawbale they are not exactly flat.  I would like
to do a tiled shower stall coming down into bathtub.  Do I try to attach
mortar board to the undulating stawbale walls? And then tile on that?  What
is the best moister protection for this situation?

Thanks very much for your thoughts, I really appreciate it.

-Orion