You'll have to forgive me, I've typed this up on public transport. Not as thorough or formatted as I’d like.
Disclosure:
I don't really play Monks because they don't really match my expectation of the concept. Only time I did was 3.0 Oriental Adventures.
So looking at the monk their are a number of things that stand out. One thing that was apparent even before the playtest was released was that, for me, many of the problems I'd have with the class would be derived from the class’ identity. What defines the Monk in my eyes is the Ki resource. Yes they punch stuff well but that is a function of their Ki, channelled into their fists for greater damage, into their bodies for faster strikes and improved mobility (or immobility in the case of mountain style). Last night a thought struck me and from there branched out into a novel approach to the class that permits a broader range of archetypes going forward. But that comes later.
To preface, there are two things that bother me about the current class design. The first is general, class locking options that could be applicable to a number of class builds. This covers things like basic combat feats from PF1 to metamagic feats being included in every caster instead of just including a general list and all classes have a single feat they can take multiple times. With regards to Monk, this refers to Martial Arts. From what we’ve seen and what the Devs have said, this is perfectly suited to an archetype. You're already spending class feats on them, so at least open it up to other classes. I would however make Monks a special case, perhaps allowing them to ignore the typical entry requirements, if necessary, and minimum progression requirements for selecting another archetype.
The other thing is the class identity, many of the features baked into the class progression build a particular kind of Monk. In PF1, some of these features were swapped out by archetypes which is now no longer possible with the archetype and multi-classing rules Pazio is presenting. Also, the core identity presented for the class is the unarmed master. I'm not arguing that this shouldn’t be part of their schtick, just that it’s only one aspect and by cleaning to it, you limit a number of character concepts. Other martial, especially the Fighter, should be able to seriously progress in unarmed combat. As I mentioned at the start, what makes the Monk stand out as an unarmed combatant is the Ki empowerment.
So in addition to making Martial Artist an archetype, opening up options for other classes and creating an opening for more interesting Monk abilities, what is there? Along with class feats like Power Attack, Monk feats that can be ascribed to mundane physical prowess (Extraordinary abilities of yore) be made general combat feats. Add a level one class feat for the relevant classes that allows them to take a combat feat they meet the prerequisites for, up to their current level. Anything that is a pressure attack (Stunning Strike, Quivering Palm) remain as it can be argued that you use Ki in some form to facilitate these attacks. Shunting out these feats opens up more interesting options permitting broader Monastic traditions. Here you could facilitate a kinetisist, ninja, sohei, etc. Also, make monk weapons a feature, and opting to use it be a choice.
An alternative to specific character themes is streams for the areas of Monk self-improvement. Mobility (speed, wall running), Enhanced fists (counts as metal, block as if hands were shields of said metal) Endurance (soaks damage instead of avoiding using temp up mechanic) , Body control (wholeness of body, Ki breathe) to complete out-there woo nonsense (Ki blasts, etherealness). Either approach can be rigid, open or synergistic as has been applied to different classes thus far. There are a good number of Monk feats that satisfy this already and they're pretty good.
So this bolt of inspiration I had? I was wondering about what the interaction between Ki and Resonance might be. Alchemists can boost their Resonance pool so it isn’t some immutable force. Then came the idea, Monks master their resonance whereby it becomes Ki. Thematically, they use Ki to enhance themselves just like Resonance is used to enhance characters generally through the bonding of magic items. I can see justification in sticking with Charisma as much as swapping to Wisdom; force of personality to master internal forces versus mental discipline to do the same.
So, like Alchemists get formulas for alchemical items, Monks could get a small list of Meditations (or any appropriate term) that mirror certain magic items, that is a list of magic items thematically appropriate for the class: Handwraps, Bracers of armour, etc. During a rest period, the Monk can meditate on a scripture, focusing Ki into particular effects. The number of active Meditations is limited but increases as they level. Meditations themselves would also scale up automatically at the same points magic items would.
I have been musing on potency and runes a little. I have no issues with potency scaling but I don’t think runes should automatically be granted so as to make the actual item Meditations reflect feel more valuable and encourage some diversification. That said, class feats could make certain runes available, like spending a point to ignite your Ki and grant the flaming rune. Stuff like that.
I don't particularly care for any of the ideas you prefaced for reasons, but tying Ki and Resonance for Monks seems like as much of a bad idea as it was to tie Resonance to Alchemist class resources.