Hmm...what could be considered all the "knightly" choices? that could be a start
Well, if it helps, when I did my Human Noble playthrough, I kinda merged ideas of 'knight' with 'templar' in my mind. So my HN was pious and extremely suspicious of magic. So I annulled the Circle, dismissed Morrigan from my party as soon as we were clear of Lothering, and refused the DR out of hand. But that's just one route to take.
The more interesting question is where they stand on the rights of the upper classes. The noble houses like the Couslands are only nobility through right of birth, so it's possible he'll hold Alistair's royal blood in high esteem. Then again, it is bastard blood, so perhaps not. Loghain is a national hero, but low-born, so your warden will definitely have strong opinions on him too (and by extension, Anora), whether he thinks of Loghain as having earned the right to be 'one of us', or whether he's an grubby social climber.
Make a stand on your warden's opinions on this (and I think you could argue a good case either way), and I think other choices will pop into place. For example, if your warden values royal blood, then he'll likely back Behlen simply because he was the old King's son. And if he is a staunch nationalist who idolises Loghain, he probably won't take kindly to Orlesians 'stealing Ferelden nobles' and won't have too many qualms about throwing Isolde under the bus to save Connor (they might even be highly distrustful of Leliana because of her Orlesian connections and past in espionage). It could even spill over into Awakenings - a born and bred fighter who admires Loghain's military prowess might want to save Vigil's Keep to secure your military strength, while the sort of royalist who puts Alistair on the throne for his blue blood might be more inclined to risk the common soldiers to save Amaranthine (the 'glittering jewel of Ferelden').
Also, though it breaks my heart because I really do like him a lot, I'm not sure I can see many 'knightly' characters giving Zevran a second chance after he tries to murder you. Assassination is, by it's very nature, highly unchivalrous. It's also works that he'd think Sten deserves his fate in the cage in Lothering.
Hope this all helps.