Monitor buying advice for 2018 MBP 13

[ScruffyDan]

I am in the process of upgrading mu home office. Currently I have early 2013 13 inch MBPr hooked up to 2 Dell 24 16x10 inch monitors.

I plan on purchasing a 2018 MBP with touchbar soon, and replace my aging Dell monitors with something more modern. I am looking at various options including 2 27 inch 1440p monitors, 2 27 inch 4k monitors, 1 32inch 4k paired with a 27 inch 1440k monitor or finally just 1 43 inch 4k monitor.

These monitors will be used for Photography (IPS is a must) and occational gaming

All of the 4k monitors listed above with the exception of the 43 inch monitor will be used with scaling. I suspect I will end up scaling the 27 inch monitors to 1440p. I am not yet sure what scaling I will use for the 32 inch monitor but likely I will try and keep OS elements a similar size to a 27 inch 1440p monitor.

The 1440p monitors and 43 inch 4k monitor would be used with no scaling.

I have a few questions.

1. Would running 2 4k monitors as I describe above cause performance issues (choppy OS animations, system slowdowns, etc) on the 2018 MBP? Would it make sense to limit myself to 1 4k monitor and 1 1440p monitor?
2. How well do 4k monitors scale to 1440p?
3. Are there any 43inch 4k monitors that have an RGB subpixel layout? Most I have seen use the BGR layout which causes issues with text smoothing in macOS

Thanks for the help!