Any way you could post paint chip photos? I don't think many of us will know those colors offhand, and looking them up is kind of a PITA just to express an opinion. (Don't mean to be snarky - Just that I think you'll get more and better feedback if it's easier for folks to respond.)

Hey, girl, no more of those tones. Let’s brighten things up. B.M. Silver Gray a

If you have a curb, you will have the cracks develop there, too. and where the walls meet the floor. Anywhere where two different materials meet or where one surface meets another that is in a different direction (known as "change of plane"). My contractor still grouts such places, too. But I did a solid surface shower that he could not do wrong. I am keeping an eye on the place where the floor meets the shower pan, all other places are in dry areas. So there it is just cosmetic. I would guess that water can get behind your tile with those cracks. If properly waterproofed it is fine, but if not, I would get to this as soon as you can. A lot of shower builders do not use waterproofing, even though it is now required. If you do a search on this forum for "Shower waterproof," you can see many discussions about it and learn what is and is not waterproof. (Redguard yes, Durock no, for instance.)

needs a littlle more attenyion than just the tile, heating and paint. Are you really lovin' that tub and tile surround???? One note of caution with the heated floor and tile installation. Lay down the heating material on the entire floor. Saving money by only heating a 'path' will result in uneven floor tile. Just a little uneven edge on a tile is a pain on a tiled floor. This is a bare feet nuisance easily avoided.