Giving the option of bailing out off the battlefield by running off to a drop ship is a bit of a no no in my book.
Using damaged mech as a bait is not a very sound tactic. Sure, you can have an immediate effect(distracting an enemy for 10-20 seconds maybe) but in the bigger scheme of things is pretty much risking a still operational mech and a mech pilot's life to gain pretty much nothing. Sure, MWO would not let you die or loose your mech permanently but with kamikaze attacks like you suggested being a common tactic(and pretty much the only one available if there would be no way to actually retreat from combat) a lot tactical realism would be thrown out of the window. Effectively this is a wounded soldier, instead of falling back to seek medical treatment, just running around hopping the enemy will shoot him, instead of his healthy squad mates.
Not only every pilot is supposed to value his own life, a good commander would value lives of his pilots and integrity of lance's mechs as this is in most cases the only resources he will have at his disposal for the following battles; he can't be wasting them like that. I want MWO combat to have as much realism in it's tactics as possible while what you are speaking about will put a huge red "you cannot die or loose anything. don't be afraid to do stupid stuff" banner on the MWO gameplay. Retreat is not necessary the act of cowardice, charging the enemy no matter what is not necessary the act of bravery. Think about it.