May I just note that I'm a bit frustrated that we have voters who are supporting "beat the dragon then absorb him" but not "beat the dragon then decide what to do next?"
It seems like something of an abuse of the approval voting system, because the whole point of approval voting is to support consensus plans that a supermajority can agree on over tug-of-war competitions between mutually exclusive plans that come down to disagreement over a single detail of the plan.
But Simon, beating the dragon was never in doubt. The vote is to decide how and what to do next, so voting to beat the dragon and then vote again about what to do makes little sense as we would end with a couple hundreds of word update, if at all, and start the voting process again. Seen that way, it makes sense that they would vote for something that has a decisive course of action. For example, I am voting for either beating him and try to make him feel the things, asking the sorcerers if he can be sealed at all somewhere, asking the sorcerers if he can be sealed inside of us, asking the sorcerers if he can be put under a masque that seals his powers so that he can go to prison and tickling him, but I am not voting for the leading option, which has us subdue it without harm and then just talk because a) it has no guarantee that it wouldn't just lie to us and b) those I asked about the option just seemed to assume we would have a later option to vote, again, what to do with it.
If it were something like, "subdue it then consult the other royals about what they think the best option would be and ask the sorcerers for non-lethal alternatives" then yes, it would be a meaningful vote, but something that is just "defeat the dragon (which would happen regardless of what we vote) then vote again for what we do next" would irk me a bit and I can't see why people would not want to vote about something they perceive does that.
Now, if you were complaining about people voting for a single plan, with no attempt to make a concensus, in order to take advantage from the votes of those who try, then yes, you might have a right to complain about going against the spirit of it. But you shouldn't complain about people not voting for a plan they disagree in a single detail if they feel the detail is important enough, like if they think the vote does not apport a meaningful course of action (voting for something they think would happen anyways and then having to vote again) or if it is about the manner in which they go about things (voting for subduing it painlessly or not, since it is about ethical vs safety concerns in case our power runs out). The whole point of it is deciding in which details you are willing to compromise and in which you aren't and even if "decide afterwards" can lead to "seal inside us", some might decide that they don't want yet another vote to decide and be well within their rights to use that as criteria.
My worry is that we may be able to seal his power but not his expertise. A master-class psychic will have a great deal of experience and knowledge at psychic conflict and manipulation. Normally he'd need to combine that with power to crowbar his influence into our heads, but we just went and invited him in, so that wouldn't matter.
And we're going to have to keep up a psychic Maginot Line inside our own head, with defenses pointing inward to contain the dragon, for the rest of our lives. Anything that could cause our concentration or willpower or focus to slip, any disaster, any unexpected magical attack of an exotic kind, could cause disaster.
I'm not worried about her failing any individual Willpower/Mind Delve check. I'm worried about her not passing ALL the Willpower/Mind Delve checks, forever, for the rest of her life. Speaking of which...
I was under the impression, from when the idea was first brought up, that sealing him inside of us is not meant to be taken as sealed inside our head. They don't want a setup like the one Jaffur has but something presumably like the Mafuba is supposed to be, with the added features of open a way to talk to it (and only talk to it, presumable with something like ki telepathy which I already explained is people sending messages to each other instead of their minds connecting or reading their minds like with mind delve) when Kakara wants to and only when she wants to (she can choose when to open the channel or not) and the possibility of letting the dragon see what we see (again, like telepathy, with the magic sending information but with only one way it can travel) with the option of shutting that down if we want privacy. Otherwise it would be on a sealed space separated from reality with no way to interact with us. Or at least that is how the idea was first pitched.
Then people started talking about accessing their power and this giving Kakara a power up, which I agree with you is extremely risky and against the humanitarian effort to reform it that the other option implies but since the vote "seal it inside of us" does not include the details of the seal, we would get to choose how to go about it after we go over our options for the seal with the sorcerers. But the main point is that the vote was not to seal the dragon's conciousness in our mind but to use our body as the physical place the dragon is sealed in the manner it would be sealed in an object but with the added bonus of a feature to let Kakara open a temporary channel to communicate with it. And maybe access its powers if some voters get their way.
Dende being a really good ki healer doesn't seem implausible, though. I think we should parse the original question is "is healing in the manner of Dende a magical ability or a ki ability," not "in the art called Dende Style, is the healing magical or ki-based?"
Given that we know ki healing exists and can do some fairly impressive things, Dende being a ki healer would work, wouldn't it?
Well, we saw Yammar using ki healing to close some of his wounds when he was fighting Dazarel so we know that at least that is within what it can do. I am inclined to disagree on Dende being a ki healer though because that presumably uses ki and Dende healed some really severe wounds in the Namek arc and the warriors seemed rested after it despite having much larger ki reserves. Plus we know that Dende knows magic because it could reactivate the dragonballs.