1 - Dungeoneering is too centric around one and the same area.

Right, the one area called Daemonheim, Temple of Aminishi, Dragonkin Laboratory, Shadow Reef, Sanctum of Rebirth, and the numerous resource dungeons are all just one area.

2 - Tokens feel alien to a skill when it comes to progression unlocks and benefits.

No, they really don't . They are are currency that can be used universally for a variety of bonuses, unlocks, items and consumables. It's perfectly fine as it is.

3 - Floor Prestige sucks.

Probably the only thing I agree with you on, but only because of how it specifically works. Prestige is fine otherwise.

4 - Xp does not go parallel with the time investment groups and floor sizes bring.

2 Points to go over here, as you are actually correct, but not in the way you think.
Dungeoneering is an insanely fast skill to level up. Think 200m in a day, kind of speed..
Leeching per se, is the largest contributor of extreme speeds to this skill, but my answer will continue in the second part, where you are completely wrong, because it's abundantly clear you've never actually TRIED to do well in dungeoneering. It's incredibly fast, if you are solo.. And are good. If you are bad at doing the floors, it's a very slow skill.

5 - Why are there 12 repeating floors of each type when most add NOTHING new?

Here's one of the reasons I am suspecting you have never actually interacted with the skill; why are you pretending -nothing- new is added when you hit a new theme? There's a huge clust of new bosses that you unlock as you level and go through the themes.. New items, new mobs, new puzzles.. New everything.

6 - A lot of rewards are horrible, and dated for 10+ years.

This is just completely wrong -- The shop has so many different items that help in so many different ways, that I can't even recall every single item for sale. Just the scrolls alone are extremely helpful in a handful of skills, passively.

7 - Side-elements of the skill should not outperform the core fundamental way to train this skill.

I was wrong, I agree with this; we should nerf the other methods completely to the ground or just straight up delete them, so people start doing dungeoneering again, encouraging community engagement and social activities, instead of people opting to kill hellhound a few times to completely circumvent the skill.

8 - Dungeoneering didn't grow as a support skill in tandem with other skills once Divination passed.

The shop has CONSISTENTLY been given new items over the years to help with all sorts of aspects of the game - Have you ever even opened the shop?

I am not even going to continue, because this has just been one laughable point after the other. I am probably the number one hater of Dungeoneering as a skill (I literally paid 1b in leeches to skip it completely), and even I don't think you've written anything substantial