I believe for the most part it will not help in better FPS since textures are not buffered in system RAM, but it may help in loading times slightly. Your FPS will mainly depend on the hardware in your GPU, and the VRAM.
it depends, what game? alot of games will not take advantage of more that 8gb, although some games will, like minecraft, you can dedicate more ram to it.
I believe for the most part it will not help in better FPS since textures are not buffered in system RAM, but it may help in loading times slightly. Your FPS will mainly depend on the hardware in your GPU, and the VRAM.
Yes, it can, in part it depends on the game. More DRAM means you can hold more data in the DRAM and make for smoother play as well as can at times increase FPS and average FPS (which is often where stuttering comes in)