Kensai Magus is the obvious choice for Exotic Weapon Proficiency (Dueling Sword), as well Weapon Focus (Dueling Sword), at level one.
Kensai Magus
1(Class). EWP Dueling Sword
1(Class). Weapon Focus Dueling Sword
1(Human). Weapon Finesse
1(Level). Slashing Grace
After that, for level 2, choose whatever Swashbuckler archetype gives you the Deeds you want. Try to stay with only one or two levels of Swashbuckler... otherwise you will be down on caster levels. The Magical Lineage (Magic) trait can make up for a 2 level dip, or two 1 level dips...
Which brings me to the Kata Master/MoMS Monk dip, at level 3...
WIS to AC (And INT to AC from Kensai)
Panache with unarmed strikes
Bonus feat
4+. Kensai Magus
BAB +6, grab the Duelist's MasterStroke feat.
Enjoy.
PS. Since Magical Lineage is a Magic trait, Wayang SpellHunter (Regional) is the go-to Magus trait for Snowball or Shocking Grasp.
I don't like dumping stats, so my array may be more conservative than others...
10,16,12,16,13,10
Level 4 adjustment is WIS
Levels 8,12,16,20 are DEX/INT (your choice)
You could also start with the Bravo Swashbuckler archetype, which gives EWP Dueling Sword, if you want to use a different Magus archetype other than Kensai.
If you do choose to use Kensai Magus with a Monk dip, you can feasibly drop your Strength stat below 10 because you aren't carrying armor. But that is for you to decide.
Trying to recover the Caster Levels lost in the dips requires the Magical Lineage trait, which negates the ability to grab the Pragmatic Activator trait that converts UMD from CHA to INT. That is why I wouldn't dump CHA below 10, but that is for you to decide.
Clever wordplay can take the place of pragmatic activator, and is a social trait.
Magical Knack not lineage BTW.
Flamboyant arcana covers a couple of the deeds and doesn't require multiclassing. I'd avoid multiclassing just for swashbuckler deeds or a single feat - you need to get more for it to be worth it. A MoMS monk's fuse styles might qualify if you really want both swordplay style and aldori style or something like that, but magus 12 is fine like it is too.
Actually if the focus is on the weapon here then a bladebound magus 12 might fit well. Assuming you don't mind your sword talking back to you that is. It's compatible with kensai, but that archetype sacrifices a lot - spell recall (+ improved) and knowledge pool are useful abilities! To say nothing of diminished spellcasting. A half-elf with ancestral arms and the bladebound archetype would work for me.
Spell combat is treated in many ways as using an off-hand weapon. Any feat with Aldori in the name either says it can't be used with an off-hand weapon or is dependent on another feat which says that. Check with your GM before aiming for any of them.
Noble duelist, right. For the trained in magic part I'd put in perhaps two feats like intensify spell and empower spell, likely used mostly with shocking grasp for which you'd want to put one trait on reducing metamagic costs. The other trait probably goes on something social since a magus gets few such skills but a noble is expected to have some; perhaps clever wordplay (bluff). Trained in swordsmanship; let's take the swordplay style to the end (swordplay deflection), that and its prereqs take the rest of your feats.
The arcana might be flamboyant arcana (deeds), spell blending (a couple of useful non-magus 2nd level spells; see invisibility, ashen path, visualization of the mind and sense vitals are all possibly useful options) and maximized magic (1/day nuke). I'm trying to avoid anything else which uses swift or immediate actions there since you're going want them for ripostes or for the feints allowed by swordplay upset during a fight, once you've spent swift actions enchanting your weapon and starting swordplay style.
To be clear, the way this works is that once you start swordplay style, if you then parry an attack you get +4 AC vs. that enemy for the rest of the round, and can spend an immediate action to either perform a feint or to make a riposte (a free attack). The parry can be either via opportune parry and riposte (costing an AoO and an arcane pool point) which stops the attack, or if you didn't use all the attacks you were entitled to on your last action you can use one of those instead, which only gives the +4 AC if it succeeds and which allows a feint but not a riposte. Complicated I know.
Guessing those are the d20pfsrd names for Aldori style/Serren's masterstroke. Well, at least you'll have less swift action congestion as a swashbuckler. Taking the noble fencer archetype takes charmed life off the list of swift action-requiring things too. On the other hand swashbuckler does little enough at mid- and later levels that it's screaming for multiclassing, maybe even Scott Wilhelm-style multiclassing.
The Aldori style line takes a lot of feats but includes no way of feinting in less than a standard action; Serren's masterstroke wants you to feint. This is an obvious problem. Also Aldori style aegis includes a replacement for opportune parry and riposte which really devalues having that deed from your class, which is the main reason to take even low levels of swashbuckler.
I don't think it's possible to use all the elements you've named in the post just above and still make a character which is worthwhile at level 12. Would you be interested if I tried making a character using the criteria 'uses Aldori style line' and 'noble fencer type' with a different class or classes?
Multiclass is one option. I'll do one with a single class, one with a more complex structure by class.
First the single-classed one. He's to be a daring champion cavalier. That's a lot like a swashbuckler but with no opportune parry, and it keeps the cavalier's challenge and order abilities though it loses the mount. Challenge & precise strike means that he adds twice level to damage a lot of the time. Order of the Flame makes keeping challenge active easier, or Order of the Eastern Star is better for defence. The feats for a human or half-elf might go
1: Weapon focus (ADS)
Daring champion cavalier 1: Swashbuckler's finesse (i.e. weapon finesse)
Tactician (cavalier 1): Precise strike
3: Slashing grace (ADS)
5: Alertness
Cavalier 6: Aldori style
7: Combat reflexes
9: Aldori style aegis
Greater tactician (cavalier 9): Intercept charge
11: Aldori style conquest
Cavalier 12: Garen's discipline
There's no good way to fit feinting in there (unless a friend of yours is willing to feint; if so get (improved) feint partner in place of the tactician feats) so I put in Garen's discipline rather than Serren's masterstroke.
OK, now the multiclass. Rake unchained rogue 2 / fighter 2 / urban bloodrager (trading 1st level power for a familiar) 1 / devoted muse 7. This prestige class supports feinting. For feats a feint-focused selection which also includes your required dueling sword is
1: Weapon focus (ADS)
Unchained rogue 1: Weapon finesse
Rogue talent 2: Combat trick (slashing grace)
3: Blind-fight
Fighter 1: Combat expertise
Fighter 2: Improved feint
5: Aldori style
7: Moonlight stalker
Devoted muse 3: Greater feint
9: Moonlight stalker feint
11: Serren's masterstroke
Devoted muse 6: Twinned feint
You'd need to be a half-elf here to use moonlight stalker. The damage is certainly lower than the daring champion even with Serren's masterstroke but the debuffs are better.
Something which gives a bonus to will saves; either the general +1 trait bonus or irrepressible if you're going to have a lot of Cha. And probably some trait which gives a bonus to your favourite social skill. The daring champion doesn't have a pressing need for traits.
You probably want to negate the swift action needed to start Aldori style. For that you need another style (preferably one you might use occasionally) to meet the prereq for combat style master. Maybe that means getting blind-fight, blinded blade style and then combat style master, or maybe you'll get skill focus (stealth) and owl style, maybe you'll get some less useful style which doesn't have a prereq like fox style in order to save a feat.
After that critical focus and staggering critical, maybe stunning critical if you have enough feats seem like they'd be simple and useful.