Thermalright supposedly has a mounting kit for AM4/AM5

https://www.thermalright.com/product/amd-am4-am5-universal-btk/

If your laptop’s port is capable of it, yes. Your iGPU is capable of it, but some laptops are saddled with only an HDMI 1.4 port. If you have such a laptop, you will need to run the monitor at a lower refresh rate.

No advantages in temperatures, at least. There is an ease-of-handling advantage in being able to relocate the radiator, as opposed to having a big chunk of metal fixed around the CPU area.