How long should I wait to apply?

[metroidbum]

...

[midnight_circus]

The general response is that earlier is better, when the classes are not full and they have plenty of scholarship money to throw around. You're above medians at I think every school on that list, so from a purely numbers perspective your personal statement wouldn't need to blow anybody away, but obviously you should be aiming for better than "meh." You put in the time to improve 8 points on your lsat (kudos, btw); it will take dramatically less effort to improve your PS from "meh" to good, or at least passable, which can only help your chances generally. There's a thread here devoted to Personal Statement advice--avail yourself of those resources ASAP and send in your app.
As for fee waivers, you can request them directly from schools. Every school should have a fairly obvious link from their admissions page, or send them an email.
Best of luck!