Flooring Tile - grout, caulk and sealer questions

hey guys.
we are starting to grout our natural slate shower. i have a few questions.

#1 they sold us unsanded grout. if our joints are less then 1/8 we are ok with this correct? what if we have a few areas where its a bit bigger? do we buy a whole bag of sanded grout to cover a 2x2 total area?

#2 i am to use caulking in every corner, correct? do ppl usualy caulk and then grout?

#3 i have been instructed to seal the slate before grouting, i have done so. what about sealing the grout? the salesman hasnt given us anything to seal the grout. is that something that has to be done?

#4 sounds a little stupid but ask but is it ok to use unsanded grout on the shower floor?

#1. My opinion is going to vary from what you have been told and sold. Depending on which slate you have used.
Gauged slate that is all the same thickness shouldn't be a problem using unsanded but ungauged is going to be much thicker than ordinary tile or gauged slate and I would use sanded grout to lesson the shrinkage that is going to occur.

#2. Correct! Either.

#3. Use the same sealer for the grout.

#4. Same deal...depends on the tile thickness and grout spacing.

:)

i know this is old but just wanted to say thx