How much physx is needed in games? Is pxei x1 speed enough for physx to work? How is the bus (64, 128, 256 bits) connected to the pcie port?

Question

Iron

1. How much do you need physx in games? How is the situation right now and how much better will it be in the future?
2. Is pxei x1 speed enough for physx to work? I want gt610 in pcie x1 and radeon r7 360 in pcie x16.
3. How is the bus (64, 128, 256 bits) connected to the pcie port? Will a 128 bit video card work faster than a 64 bit video card, provided they are inserted into the pcie x1?
4 Do I understand correctly that if gt610 is added to the radeon r7 360 + AMD Athlon II X4 635 bundle (for example, in pcie x1), then the CPU load will decrease, I will have better quality and more games will play?