This is my first post to this forum (I've mostly been on the Kitchen and Appliance forums). I apologize in advance for the rambling nature of the question. I'm still trying to get an idea for what we want to do.

We're looking to upgrade the shower in our 19yo master bath (we're the original owners). We currently have a Delta pressure balanced mixing valve, and a handheld shower that we're not thrilled with. All of our metal finishes in the bath are polished brass, so we probably want to stay with that. The shower enclosure (rougly 3x6 with sliding doors on the long side) is tiled with ceramic tile.

We're not happy with the amount of water we're getting from the shower. A plumber has told us that our water pressure is fine, but that we're limited in the volume we'll get because of the 1/2-in supply lines to the mixing valve. Does that make sense?

If so, and we decide to upgrade to 3/4-in lines, I'm sure we'll have to take out at least some of the tile, which leads me to question 2. Can tile normally be taken off cleanly, and replaced? We have a lot of the same tile in the bathroom, and don't really want to retile everything. We are afraid that once we get started, the shower will probably need to be retiled anyway. On the long tiled wall, you can push on the tile at the bottom, and see that it moves (I'm guessing that's not a good thing). The shower pan is a solid plastic with a center drain. We're not thrilled with it from a looks perspective, but it's servicable, and we'd just as soon keep it if we're not taking everything out.

As far as the shower itself, I'm thinking we want to replace the pressure-balanced valve with a thermostatic valve. We also want to have a fixed rain-type head along with a handheld (possibly a stick-shaped one). The two heads would not be intended to run at the same time. What's the best way to configure the components? Separate diverter valves for each output? An external diverter on the fixed head for the handheld? I see lots of options, and it's not clear which way to go. I'd be thrilled with brand recommendations, but they have to be available in polished brass.

Thanks in advance for any advice on any of the questions!