> Without GPU acceleration, a browser won't work fine

Disagreed - it does work fine. Maybe there's specific niche features that don't work but I have yet to come across them. Only problem is video decoding which works but uses lots of CPU so terrible for laptop battery life.

It really depends. It may work fine, but it'll be using more CPU resources than it would with the GPU.

It probably depends on what exactly you do with it, but almost everything works fine. Games and 3D graphics may suffer, if you have a slow CPU.

No problems here. Even Google Maps is fixable.