You don't need to actually have the skill reqs as a Class Skill. So you can just funnel points into K:Arcana until you've got five ranks and not worry about actually being particularly good at it. I was wrong about the spellcasting interaction last night though, you need three levels of Monk to qualify for Monastic Legacy.
So basically you
All of this about fighting with your tusks and claws? Unnecessary in this build, because your Huge Walrus Kung Fu will be mighty as all get out, hitting as Gargantuan in regular, everyday sorts of flurries. This is all about pure mass and size, Walrus-slamming people across the battlefield with Awesome Blow, fully equipped with the best levels of druid buff spells. The test build I did didn't worry with multiple styles, it's all Dragon Style and power attacks.