Identifying motors

New to this board and I have a LOT of questions but I'll start with 3.

1) How can you visually tell the difference between the 1.8 and 1.4?

2) Once you have the doors apart how do you remove the window motor? Passenger side front.

3) I was told I need a front exhaust pipe. Is this the pipe that comes after the exhaust manifold?

Thanks