Therefore, you have to go by your shower needs and not by: what do people have now? Or what is more expensive or worth more than what we have in our rental apartment?
I don’t care what "people" have. WE want to have a rain shower. We have that now in the rental apartment as well and we want it in the future too. I even replaced the shower head in the rental apartment to get more water flow and a real "rain feeling." It’s about what we like and not about copying a show home. Our rental apartment is very well equipped. We will not be able to outfit the house identically throughout. For example, the smoothly plastered ceilings would be a cost killer, as I see it. It would be a misconception to assume that one necessarily lives worse in rental properties.
So, any halfway decent plumber should be able to provide a rain shower...
I also assume that. It is not said that the general contractor (GU) plumber cannot do it, but we agreed that we clarify our plumbing needs and then see under what conditions that can be handled by the GU or if it will actually be outsourced in the end.
I wouldn’t start coordinating but rather let the GU do everything. In the end, you’ll be to blame because the process wasn’t planned well.
Then I have to try to take the opposite approach. Plan everything with the GU plumber and then see afterward if it is feasible for a reasonable additional cost compared to a competitor.
Regarding the electrical work, it was recommended to outsource the service but plan it with the electrician who would otherwise do the GU service. However, I checked; there is nothing about home automation, etc., on the page. At least for the roller shutters, I would want to do something like that.