Is their a way to gain immunity to the staggered condition? Obviously the earlier, the better. I want to play the goblin bouncy ball with the Roll With It feat.
All the stuff I could find was either mythic, or L16-20 capstones.
Guardian (mythic) has indomitable.
Search paizo for staggered or staggered +immune
Instead of avoiding staggered consider playing a class/playstyle that does not rely on Full Round Actions. The vital strike feat line, the Startoss Featline, and other unique standard actions are your go to options
You could also go for a reach build since staggered does not remove your ability to preform AoOs.
Spells are always an option too.
My preferred build would be a monkey style Intrepid Rescuer roll with it Double Chain Kama wielding goblin MoMS. You roll around, fall prone, and get free AoOs against people who attack you thanks to "you are your own ally," and if you end up prone from roll with it there is no harm done.
The spell Placebo effect will do it. Assuming that you don't want to lose a standard action to casting it, the two metamagic reducing traits and quicken spell make it a 4th level spell; minimum character level 8 for a psychic. Or if you have some minion who can use a wand, whatever level you can afford a wand of a 2nd level spell.
Similarly with Remove paralysis and a {cleric, oracle, shaman, warpriest or inquisitor} but it's more restricted in use outside fixing your staggered condition. Though a warpriest using fervor wouldn't need quicken spell which would make it easier - minimum character level 4. They might want to pick up silent spell so the same spell could fix it if they got paralyzed.
Edit: I was looking for a different idea for Ten'shun's tournament. Now I have one.
Paladin or Mesmerist can swift action heal to remove the condition.
Thank you everyone!