In my experience, Code doesn't cover the "style" of the fixtures but pertains to how they operate.

Code is going to be different in different jurisdictions. I am in California so I had to deal with shower fixtures that had restricted volume flow as well as not being able to have more than one fixture operate at the same time. I also dealt with an arcane issue relating to whether there was some kind of valve in my handheld which prevented water from going back into the system.

There are other Codes that relate to water temperatures and mixing valves for example.

If you are inexperienced in terms of plumbing, I would leave selecting plumbing to the experts because that way they are responsible for having all parts available - in compliance - not defective etc. When I remodeled, I selected the style I wanted and conveyed that to my designer/GC and they were then responsible for ordering everything that was necessary and proper.

Are there codes for max flow rate? The flow rate says 7 gallons per minute.

Call your building department and ask them what the requirements are. They are usually very friendly and helpful when you're trying understand and follow code, not circumvent it. They may follow the Uniform Plumbing Code, or they might be more strict. That is the case in California where I work.

Your contractor really should be able to give you specifics too.

That Kingston Brass shower fitting does not have a pressure balancing valve.

http://www.ecodes.biz/ecodes_support/free_resources/2010Florida/Residential/PDFs/Chapter%2027%20-%20Plumbing%20Fixtures.pdf

Relevant section is P2708.3

I once did a job where we installed a pressure-balance valve in the line before the fixture. It was a scenario like this - the client fell in love with a fixture that did not have a pressure balance valve. The plumber came up with the solution of adding the valve before the fixture.