Clovenhoof said:
#1: Tank. Noble has Heavy Armour Proficiency AND the money to make use of it, so get a Large Shield, Full Plate and Great/Visored Helm. You'll still get hit quite often due to your crappy Defense, but DR12 goes a really long way and is almost impenetrable. Let the mooks slash at you futilely while you just stand there and laugh.
Yeah, if there's already a soldier (assuming fighter = soldier) in the party, then heavy armor isn't likely to be suicidal like it is in our campaign. Doesn't help with offense, though.
Clovenhoof said:
#3: to deal damage, max out Bluff and take the Power Attack and Improved Feint feats (and maybe Skill Focus Bluff). You can feint one opponent and attack him in the same round. A feinted opponent has DV10, so you can crank up that Power Attack.
You might also add in some Thief levels for that nasty Sneak Attack, which applies every time you have feinted an opponent.
It seems to me that the character already exists and that there isn't a lot of rewriting that can be done nor does the question seem to be about how to make a character better at combat by ceasing to waste time as a noble.
I don't know that there's a great need for Improved Feint, which takes two feats the normal way (using up all three feats that, say, a 3rd level noble should have). I'd much rather take Cleave as it's Cleave at lower levels that is the hotness of PA/C where PA gets a lot better when the BAB gets around 4 or so. Of course, the assumption is that the character is using a bardiche or greatsword since there's no reason not to.
Knowledge: Zingaran Fencing School would be an interesting way to go since it gives stuff like Improved Feint for free, but it's not likely to help this character much since you still need damage output to make it worthwhile and K:ZFS limits to broadsword or arming sword, meaning pretty much you want a bunch of Sneak Attack - not exactly a noble's strength.
No, resign yourself to being a spearchucker. It's okay. Everyone in our party except the 23 STR barbarian is a spearchucker at least some of the time, almost everyone is a spearchucker all of the time - we run into so many things immune to Sneak Attack stuff that even the thief is regularly neutered. How do you help as a spearchucker? Well, the tank thing helps take pressure off if you form good combat lines, but mostly, you embrace the aid another action. It's amazing how often our group forgets that our impotence makes aiding the killing machine the only reasonable choice. Just selfish to swing on an enemy futilely. Also, when your attack is good enough, remember to fight defensively when aiding another. The noble was even meant to be a spearchucker with the horridly undesirable Lead By Example power - relish your ineffectualness. Relish!
Not that I particularly understand the grapple rules, but maybe you can pick up Improved Grapple to become a countergrappler so that the hitters in the party don't get bogged down in tedious grapple wars.
At higher levels, can start in on the Steely Gaze, Menacing Aura, ..., "Look at me and my party kills you" (or whatever the end feat is) path. Of course, by 6th level, a noble should have an army to do the fighting which may or may not need any help.