I've tried reading the new book forward and back, and I still can't quite sort out where focus spells determine their ability modifier for attacks and DCs. This seems obvious for actual casters, but when the noncasters get their toys, I wonder.
I vaguely remember the monk's Ki Blast relying on the class DC (so a Strength monk is using her mighty magic muscles), but I don't know if this is a specific or general sort of thing.
It is something that should be coming out of class features. So the champion, for example, says that it's spellcasting attribute is Charisma, and the monk is supposed to be Wisdom (which isn't in the description and has been acknowledged as an error).
So my monk still has to be wise? If the character concept I have in mind didn't require it anyway I'd be mildly annoyed.
That depends on what you plan to use. For Ki Blast, which relies on focus spell DC, wisdom would be important. For Focus Spells that don't care about the DC, like Ku Rush or Ki Strike (and all of them purely physical monk feats), your wisdom wouldn't matter.