DreamTourist: You'll have better luck finding class build advice over at Owlcat's forums.
https://forum.owlcatgames.com/c/pathfinder-wotr/class-builds/20 There's already a bunch of posts with quarterstaff master monk builds.
Cartesii: I tried to find a build there yet, but most discussions are a bit weird :/.
No real build there yet. But thanks for the advise. I guess i need to wait a bit, till more builds are out.
I was curious enough to hire a mercenary/Pathfinder and pumping their experience point to level 20 - that is how I would try possible builds.
This is a suggestion - though be warned: I am not an expert. It is something how I would imagine a quarterstaff master monk. It is a pure build since I think it makes sense for a pure build to get the extra weapon damage at level 20.
Lvl 1
Human - Hermit
16,17,14,10,15,7
Toughness
Diehard
Blind Fight
Nethys
Lvl 2
Dodge
Lvl 3
Weapon Focus Quarterstaff
Lvl 4
Dex +1 = 18
Ki Power: Barkskin
Lvl 5
Combat Reflexes
Lvl 6
Crane Style
Ki Power: True Strike
Lvl 7
Hammer the gap
Lvl 8
Wis+1 = 16
Ki Power: Sudden Speed
Lvl 9
Critical Focus
Lvl 10
Improved Critical Quarterstaff
Ki Power: Wholeness of Body
Lvl 11
Sickening Critical
Lvl 12
Str+1 = 17
Ki Power: Restoration
Lvl 13
Staggering Critical
Lvl 14
Ki Power: Diamond Soul
Improved Blind Fight
Lvl 15
Dazzling display
Lvl 16
Str + 1 = 18
Ki Power: Shout
Lvl 17
History of Terrors
Lvl 18
Ki Power: Abundant Step
Trip
Lvl 19
Crane Wing
Lvl 20
Dex+ 1 = 19
Ki Power: Quivering Palm
I skipped the skills since they are not necessary for combat. It is not perfect so I welcome feedback from more experienced Pathfinder players. I also exclude Mythic feats in this one, but keeping in mind there are stuff like Archmage armour and additional feats. I usually play quite defensive, so I mixed in some Crane style. It is up to someone's preference whether to focus on that or something else.
After level 14 I did feel like I put the most important feats already into the build, and the rest became more a quality of life choice which are also useful in combat.
@Cartesii > feel free to ask for details about some choices of mine. It is the best way to get a feeling for this stuff so you can come up with your personal best build without relying on someone elses. ^.^
Edited stats since Quarterstaff does not benefit from Weapon Finesse