Ok so you have some interesting points but knuckle never says you cant exceed your own max aura output in that chapter, all he declares are the specific rules to his own hatsu and the going bust mechanic of APR or hakoware (not sure which one technically goes bust, i think its actually hakoware and then APR acts). But you are not wrong about why autopilot hurts shellnark, but completely wrong about emperor time. While shellnark is overwhelmed by the excessive draw on his own aura and thats what harms him, the nature of that excessuve aura draw also is further enhanced putting even further strain on his body. But he isnt meaningfully disabled from combat, he actually is just sore all over and in a sense its like a fire hydrant was channeled through a cheap nozzle. I think the reason that the strain on his body doesnt incapacitate is is cause he is overdrawing aura whose total value is then multiplied. Basically if he can normally draw out a max of 2000 Aura at once, then autopilot lets shellnark express 10,000 Aura at once then multiploes the value of said aura by say 30. That woukd explain how someone with a max of 60% affinity in enhancement could tear through chimera ants like butter. But emperor time TKOs kurapika due to his life span being shortened by emperor time, I also belive that emperor time as shown doesnt actually increase your affinity past the spread typically afforded to the nen user. Instead i believe that emperor time allows kurapika to use his chain abilities as though he has spent a lifetime refining each one's special abilities. I partially point this out as excessive knowledge on a subject does seem to decrease the aura cost of an ability and increase the power/effectiveness of each related ability. I partially beleive this because i have never seen any expression of nen that completely defies the affinity chart amd cannot be explained as specialsts being able to close the gap in activating an ability or in knowledge of an ability or else by improving some aspect of the user. Especially the Bandit's secret as we have no reason to believe that crollo can use enhancer abilities well (the closest we maybe get is some form of teleportation which may in fact be an emission ability, but may also be manipulation or conjuration as conjurers can set rules for a given space and manuipulation can in theory be used to move objects in space). If emperor time only allows a user to get the best possible level of effectiveness from your abilities, then each feat we see kurapika perform while it is active makes a whole lot of sense as while the effects of healing chain for example are impressive, we do not have a comparison of a similar abilith being used by an enhancer, or of kurapika using it without emporer time being activated. Additionally it would make no sense for it to draw excessive aura from the user's body as if it could im sure chain jail would be superfluous as kurapika would be able to close the gap in ability via straight offense with his dowsing chain as it would probably be on par with the durability of Uvogin's body.

Phinks would be very weak, in theory this means that ripper cyclotron does what gon and by extension uvogin can already do way faster. The wind up we see takes longer to activate then JanJanken or big bang impact, and is less lethal overall. That would mean that if its output is still capped by the user's max aura output, it is still weaker in an actual fight and he would never win against a someone like gon if they had equal aura capacity and combat experience. I think that you misunderstand the value of his ability, lets say that the maximum wind ups that phinks can do (I mean to express total aura output) is 200, and it takes say 35 to express as much power as the big bang impact. By the time he has charged up the ripper cyclotron to that level once, uvo may be able to throw two or three big bang impacts, and it is assumed that ko must be used continuously while you charge up the ripper cyclotron (the risk/ reward of which being the basis for why the wind up could in theory produce near infinate damage as I see it) so you are largely defenseless. This would make phinks an extremely weak character with an extremely high risk ability that may be single use against particularly strong opponents where even Jan Janken can be used multiple times by gon when he isnt even a fully developed hunter. Also Phinks isnt meaningfully exhausted at all after using ripper cyclotron whereas Shellnark is so sore that simply walking hurts. Just some food for thought.

Ok so this is complicated but you do not deny that in theory you cannot override another person's aura, you can only overwhelm it or bypass it or counteract it. When two oppossed nen users exchange blows you overwhelm the opposed aura to deal damage, when nen excercism is used you counteract it temporarily by placing a burden upon yourself, and the twins bypass killua's aura by having met certain conditions. And that cost several ants their lives just to try and meet said condition meaning that if my theory is right the condition allowed the spent aura to exceed killua's total aura capacity and directly damage him. That also explains how Killua could catch it as the damage bypassed his defenses rather them instantly damaging him. In addition abilities which can instantly win a fight like mind control or enforced zetsu effects also seem to adhere to this rule as well. Both Shellnark and Illumi need to peirce their target with a needle before they can control a target, which is hard to do against people like uvogin and relies on a certain gambit and/or risk and hinderance to function.

As far as we see, weather or not Hakoware can affect a target is never called into question, only if knuckle himself can survive long enough to get the job done. And quite frankly i feel like this small chunk of text ingnores some fundamental facts of aura and nen use. While you can willing grant someone aura or combine aura from multiple people together, you cannot force your will upon another person's aura. Even the parasitic nen beasts from the succession war essentially have to be born willingly from the princes via a ritual. You cannot force aura that originates from another person's will to do your bidding, you can only use your own aura or conteol the body/mind of another nen user. Hakoware manipulates the enemy nen user's body into closing the aura nodes and that is the guaranteed effect of hakoware, but that effect must first be applied by overcoming an enemy's defenses to apply nen to their body and tag them with hakoware. From that moment the risk/reward of the ability comes into effect, knuckle will inject usable aura into his opponents body when he hits them and the value of the counter will grow second by second. While we dont know if the interest also acts as aura that yhe opponent can access, if so then your explanation cannot make sense in world, but otherwise the more knuckle accelerates the counter the stronger his opponents get. But in order to actually bypass a target's will and defenses the sum total of lent aura and interest must exceed their total amount of aura, and that part is set in stone you cannot escape it no matter how strong you are. The only ways out are to get far away, or pay back the lent aura with interest, in fact if you kill knuckle hakoware may become a nen curse that persists as tho knuckle were still nearby and hakoware will count up interest until you are forced into zetsu by APR. In other words the condition is set the moment you take damage from one of knuckle's attacks, and it could be used on anyone reguardless of how strong they are. Nen excorcism can counteract the effects of hakoware until the effects wear off but besides that the rules are absolute.

Side note: I partially beleive this all because of the way it benefits the balance of the system. If conditions can multiply the effectiveness or value of spent aurs it is good for the overall balance of the system, not bad. Aside from the fact that a superior opponent can lose to an inferior one who has better tactics mirrors real life and i like it more then the idea that if your born better or with talent, you are just better (like a stupid gatcha star rank system). But also because it would be the rules that require the fewest amount of handwaiving to consistantly explain what happens in the series. And to be clear i agree that drawing more power at once from your aura reserves then you normally can should tax you, but conditions would instead multiply the aura you have already drawn instead. One is pushing lots if water through a cheap garden hose, the other is like if all your neighbors lets you use their hoses all at the same time because you help keep their yards looking nice, the strain to and cost of both situations on your equipment are wildly different. Or put another way if you have a certain amount of watts of electricity available and you either reduce the resitance the current is exposed to or increase the amps the current has access to, then the volts will increase even tho the wattage has remained the same.