A Dawnflower Dervish / Dervish of Dawn (it's the same thing, btw; due to copyright issues d20pfsrd had to rename some things) does not need weapon finesse as long as you "stick to the plan" and just use a scimitar for melee.
Dervish Dance feat specifically gives dex to attack and damage with scimitars. It just *usually* requires weapon finesse first, making the attack part redundant.
Human is a good race due to the extra spells known favored class bonus, and the usual bennies of bonus feat and skill points. Azata-blooded Aasimar gives the dex/cha you want w/ no penalties and has a favored class bonus of quicker advancing performance (pick inspire courage, of course) and is also great.
For feats, you might not want to bother with Arcane Strike at all. If you go by the assumption +1 to hit is worth +2 damage, Arcane Strike is inferior to Weapon Focus (hardly a great feat in its own right) until level 5 and isn't better till level TEN. And it takes a swift to activate, which could get annoying. Beating DR /magic is nice and all, but really shouldn't be much of an issue until you actually get a +1 scimitar.
You have a required "free hand" that can't have a weapon or shield, so use it for something. Currently, there are 2 valid options.
1. Take the Flagbearer feat to give a minor buff to yourself and allies. It's nice because it's only 1 feat.
2. Go for Crane Wing. This requires Dodge, Imp. Unarmed Strike, and Crane Style, and BAB +5 and obviously is a hefty investment. For it, though, you get +1 dodge AC and can take -2 to hit for +4 AC and deflect one melee hit per round, pretty nice. Later on, you can get Crane Riposte for a free attack when deflecting a hit 1/round.
For other feats, I really like the combo of Enforcer + the Blade of Mercy trait. You now intimidate on every attack, basically. If getting Dodge for Crane Wing, Osyluth Guile is also pretty nice later on.
At 11th level, you want Discordant Voice for your feat. It's a no-brainer.
Eldritch Heritage is also a good feat for a charisma-based caster. Arcane bloodline gives you a familiar and is the best choice. If starting at higher levels, Improved Eldritch Heritage (Marid bloodline) - requires level 11 or higher - gives you an unlimited use per day supernatural (ie, no SR) 60 ft line that deals untyped damage and blinds, with the blinding negated by REFLEX! The bloodline is worthless before then, but Water's Fury makes it all worth it and is a great ranged option for a class lacking in ranged offense.
I would not wear a buckler on your sword arm. You'll take a -1 to hit and lose the AC bonus each round you attack anyway. Hardly seems worth it just to get more AC before your 1st turn in combat and on rounds you cast spells...