Since you'll have two means of using martial flexibility you want feats which help as prereqs. Since you have 14 Str, generally poor BAB, and will lack higher-level buff spells you want feats which improve accuracy. Since your Cha is great you probably want feats which can add your Cha as a bonus to things. Finally you probably want extra revelation. No you can't get all of those.
I'd suggest starting with combat reflexes for extra attacks at your best bonus with a long spear, and improved unarmed strike as the bonus feat. Assuming you get the revelation which gives you martial weapon & armor prof. at 3rd (battle oracle, right?) take weapon focus in a reach weapon then. That gives you a good base to use martial flex with. Extra revelation at least once after that, probably get osyluth guile when you can.
For equipment, when making a melee character while at a mechanical disadvantage you want to focus more on the big six, not less. Still, a ring of revelation and robes of arcane heritage are things to consider when you've free cash.
Half-elf also has access to the race trait Bifurcated Magic - which means another +1 to CL, stacking with Multidisciplined. Yup, the race trait doesn't stack with the popular Magical Knack, but they overlap - if you also take the latter, you will get a final +1 to CL for one class, at least. If you want to keep your current traits, the feat Additional Traits is an option. You don't get anything out of both suggested traits at level 1, anyway.
When it comes to feats, I recommend Quicken Spell as soon as you can cast level 5 spells (level 14). Some level 1 buffs stay relevant, and you want them up quickly in combat, without sacrificing full-attacks.