Would you allowed a draconic bloodlined sorcerer. Also what are your feelings on Kobolds for this game?
*If you are forcing people to go, Monk, don't ever go anything below a 30 point buy, ever. If you want to randomize, a similar setup of mine akin to a 3d4+6, reroll 1's will give you 12-18 for a not ground-breaking, but a "special hero" feel to allow for Monk (MAD class)+Something else stats. Such as Monk/Sorcerer, where Charisma is the Monk's dump stat, you need every single attribute to be viable here.
*Unchained Monk is a balance fix because it was needed in the system for them to utilize their intended role within the system by the numbers without a true hardcore char op setup to just be viable. The same with the Unchained Rogue and Barbarian getting the same treatment.
*No harm no foul in letting folks integrate the flavor archetypes of the base monk into the Unchained Monk as long as they integrate the abilities replaced at the respective levels the Unchained Monk gets them. This includes deliberately taking Ki Powers to have them be replaced by the archetype, generally, I think 1 level later than normal. There are no major balancing issues here.
*Unchained Ninja, by Everyman Gaming is something I would suggest, a player brought it to my attention for my gestalt game and it's balanced in a similar manner to the other Unchained classes, making Ninja viable in the same way the new Unchained Rogue is. If you want an Asian theme, I'd suggest utilizing it.