I recently saw a Rime Spell combo ,Enforcer with a cruel whip and wonder if this makes sense combined with a maneuver magus.
Elf Magus Kensai
Magical knack (Magus),wayang Frostbite
1: Weapon finesse,weapon focus whip
3: whip mastery , wand wielder
5: rime spell, enforcer
A big question now should I go 3 levels fighter weapon master (8-10) for advanced weapon training focus for the d10 whip.
Also with the deed arcana. Is sw precise strike and slashing grace combo possible?
3 levels of fighter would give you a 1d6 damage whip, not 1d10. The advanced weapon training is based off class level not character level. So no, not worth it at all.
If you're going to be using enforcer you might want a trait like bruising intellect to make your intimidate skill useful. Cha 7 is not a good place to start using intimidate from, and if you don't multiclass you can drop magical knack.
The Arcane Deed magus arcana is pretty much useless now. It treats your swashbuckler level as zero which means precise strike adds zero damage. Flamboyant Arcana is still useful though.
I would not multiclass as weapon dice is not worth it for this build and Your main concerns are massively debuffing while moderately killing them. You will not have the nova damage of the shocking grasp builds. Also, 1d4 vs 1d8 is not worth a dip for. Higher Level spells greatly outweigh that minor option.
Take bruising intellect.
I would probably do this spread:
10,18,13,17,10,7 for my stats. (Put +1 into Int @ 4,12,16 and +1 Con @ 8)
I would take the Arcane Focus Alternative Racial for Elves. +2 Racial bonus Concentration checks while casting arcane spells defensively.
If you want to bump your damage my suggestion is Weapon specialization if you can fit it in later in the build. As it will perform better than the fighter dip. You want those sweet higher level spells like D. Door, Fireball, Cloudkill, Polymorph spells, Stoneskin, Fly, Sirocco. Much better than what a few levels of fighter are going to offer you.
I'm pretty sure Magus only counts as Fighter for qualifying for feats, so as others have mentioned, you would only get 1D6 out of Focused Weapon with a 3 level dip. A 1 level dip into Warpriest would get you the same damage plus Weapon Focus. But it's probably not worth it. (EDIT: Especially since you already have Weapon Focus from Kensei. Plus there'd be the temptation to go 2 levels of Warpriest for Fervor).
You haven't mentioned what you're going to use Wand Wielder for, so I'll go ahead and offer that blade lash is likely the better option than truestrike in most situations. The reason is that blade lash grants a trip attempt as part of the spell, so with Spell Combat you can trip, then attack the prone target all in the same round. With truestrike you can only trip (at least until you have an iterative). +10 on top of a reasonably optimized trip CMB is plenty to trip most level appropriate opponents. You can always keep a wand of true strike around just in case.
Phalanx Formation would be useful to allow tripping/attacking over your allies without penalty. If you do eventually plan to pick up Improved Trip, I'd go with Dirty Fighting instead of Combat Expertise for the prereq, as it actually offers a useful benefit for you.
With Enforcer, look at the Cruel weapon enhancement. EDIT: Nevermind. I see you already have that.
Thanks for the clarification, but then it would be a 1d8 since Magus Kensai treats himself as a Magus -3 for Fighter Feats etc (starting LvL 7).
Fighter Training (Ex): Starting at 7th level, a kensai counts his magus level –3 as his fighter level for the purpose of qualifying for feats (if he has levels in fighter, these levels stack), but forfeits the benefit of such feats with weapons other than his favored weapon. This ability replaces knowledge pool.
For the purpose of qualifying for feats, not for utilizing feats.
Since you are often going to be dealing non-lethal damage you might consider the Sapping Weapon Special Ability to increase your damage (and possibly add fatigued).