McP77

I've not seen the exact tile so will assume it's a full bodied porcelain.

1) It shouldn't do as a porcelain tile has properties similar to glass. The only thing to consider is if the material is translucent like marble. You may see the adhesive showing through the tile. Try holding the tile up to the light.
2) You can seal before laying but if you work clean then you'll be alright sealing after laying/before grouting
3) If you have properly sealed the tile prior to grouting then you can grout normally. Best thing is to try it on an offcut first just to make sure.