Well.
I think the key is to think in terms of a morality of virtues rather than consequences. You seem focused on the concept of Honor, and with a pretty good conception of it. Along those lines:
* Never abandon a mission, nor accept another mission until the previous one has been fulfilled, rescinded, made obsolete, or shown to be deceitful or wrong. If you are accept a quest to find the poor woman's son, you cannot go on a sidequest to save the kingdom.
* Deceiving the enemy is a big no-no (you DID ask for extremes). You would not flank a foe, nor lay in ambush, hide or use invisibility. Never accept a surprise round, let it pass by merely announcing yourself so that your foes may face your fairly. You may need to clearly announce your presence when you walk into enemy land. You should trust to the enemy's lack of knowledge, for this is dishonorable - do not use guile in war, do not distract your opponent and cast him into uncertrainty.
* There is no honor in vanquishing a foe less equipped than you. You shall not charge a foe with weapons if he is without one, nor fight with armor when your opponent has none, nor fight from horseback when your opponent does not. Should your foe drop his weapon, or armor, or dismount, he is without honor - this does not mean you should lose yours, face him as he wishes you to face him, in this you shall find great honor.
* There is no honor in vanquishing the wounded and dying. Never attack a dying or helpless man, never attack those wounded when you are hale - let them heal first. Should they attack you, the honorable thing to do would be to attack them but while handicapping yourself.
* A man cannot be honorable when he is fleeing. Never retreat, paladins do not fear. Trust in god that this is for the best.
* There is no dishonor is fighting the best your can. If a man assualts you armed when you are unarmed, there is no dishonor in fighting back. If a dragon swallows you, there is no dishonor in cutting its gut. But do not do the same - do attack with arms and unarmed man, do not depry another his abilities (e.g. Dex modifier) in battle.
* The company you keep reflects on you. While you cannot force them (you have no authority over them), it is dishonorable to let dishonorable plans come to fruition. Announce the ambush, light a torch as you advance under darkness, throw away the poison. Act so that your battles will be fought honorably.
You may want to consider things from the prespective of other virtues:
Charity: How much should you give? To whom?
Valor: Should you ever refuse an honest request for aid?
Piety: Should you accept the service/worship of ther deities? How shall you oopose it? What service are you to give?
Mercy: Should you accept anyone's surrender?
Responsibility: Killied the orcs? You should look out for their children and wifes.
You DID ask for the extreme, so I went there...