You can see every single player, staff and teams' vital attributes. Basically, with the first two, you can view their current ability and his attributes (including hidden ones like Injury Proneness and Important Matches), and their potential ability (you can see what their attributes will be in the future). You can also view his positional rating, so you know exactly where to play him and how to train him.
Probably.
Not necessarily, but it will take a huge chunk out of it.
No, because I like a challenge.