The CPU should be fine, but if you have the budget you can go with the Ryzen 5 2600 for 60$ more.
You should go with a B450 Mobo because it supports ryzen 2 out of the box... on that A320 a BIOS update may be required. I'd recommend a better PSU.. . VS series have low quality components. Higher frequrncy RAM will also benefit ryzen quite a bit in games.... that's why I went with DDR4-3000 memory.
The R3-2200G is a quad core with Turbo Boost at 3.7 GB. And it doesn't overclock particularly well.
I would guess not. But I would upgrade the processor (the AMD RYZEN 5 2600 6-Core is about $60 more). The price difference between 2400MHz and 3000 MHz RAM isn't much.