Will this kit work with my AMD Ryzen system?

Yes on DDR4 Ryzen boards, but it has no EXPO profile. You enable XMP or set 3600MHz and CL18 timings manually, and some older Ryzen chips top out below 3600MHz.

Is 32GB in two sticks better than four 8GB sticks?

Two 16GB sticks are easier on the memory controller and leave two slots free for a later upgrade to 64GB. Four sticks can also be harder to run at 3600MHz.

Will it fit under a large air cooler?

The heatspreader is tall, so check your cooler's clearance. Many big tower coolers overhang the first memory slot and force you to raise the fan or pick low-profile RAM.

Do I need G.Skill software for the RGB?

No. The lighting works through motherboard RGB software from Asus, MSI, Gigabyte and ASRock. G.Skill's own tool adds per-module effects but is optional.

Is this kit good for gaming?

Yes. 32GB covers modern games and background apps, and 3600MHz CL18 is a good match for DDR4 gaming builds. Gains over 3200MHz are modest but real on Ryzen.