My character is a lawful evil character. Therefore, he's really lawful and really evil. So he's cruel and will use any loophole left in any contract, but will keep to the letter of the contract, if not the spirit.
What skill would you use to reasonably expect the cleric to know things about contracts?
* Diplomacy is fitting
* Linguistics would fit (wording of the law if very important and leave many opportunities)
* Knowledge (local) mentions local laws
* Profession (barrister) is really fitting, but you wouldn't use it much
I maxed out diplomacy already and I've taken a bit of Knowledge (nobility).
So there are many overlapping skills and taking all of them is impossible if you want a playable character.