Diplomacy Problems

Can somebody explain to me how this works, because as it stands it seems like the system is broken. The percieved value of everything the computer has is always 4 to 5 times greater than what I have, when I have exactly the same thing.

Also, can somebody explain the power rating and what factors the computer calculates when determining how powerful a faction is? Because it seems like even though I'm the strongest, people like to start war with me all the time.