Here at Riot....
"We believe that too many Traps in urf are unhealthy for the game, we wouldnt want Fizz to have any trouble casting his Trollpoll now would we? so we are limiting the amount of traps a champion can have.
We are also going to ignore invaulnerability in the game because being invaunerable 50% of the time will make big munnie and lots of fun."
Look all im trying to say is... you guys Nerf traps that need to be placed in one area to be effective....you nerf heals for being to strong. but you let invaulnerability stay untouched? i say Remove all of the shitty restrictions you put on champs... that is how you widen the champ pool on Urf.