I'd love some expert advice...

We're planning on installing black Vermont slate floors in our kitchen, entranceway and bathrooms (including on the walls and ceiling of a shower). I've found a lot of conflicting opinions regarding sealing the slate (including "In my estimation, most slate floors are better left without a finish on them." from Tom Silva on this site).

Can any one give me a more detailed discussion of the pros and cons of sealing? And how will grouting affect the slate?

Finally, is it possible to maintain the floors (and natural wear and tear) with mineral oil or something natural? We're also installing soapstone countertops and I'm quite comfortable with their maintenance and how they develop a patina of wear over the years. I was hoping slate would be a natural compliment in that regard.

Any help would be appreciated!