A new player coming in learns from basic OW mobs while questing not to stand in the aoe on the ground. Which constitutes the entirety of the first boss. The 2nd boss introduces Adds. The 3rd boss is the one that introduces that some aoes are not given a warning marker and need to be figured out, they can look to people who have run the dungeon before on what to do. Though the AoE in question in general has not proven to be bad enough to cause wipes (from what I have seen). The 4th boss shows its a combination of the 2nd and 3rd boss. The last boss introduces LoS attacks, but is otherwise a combination of the previous bosses before it.
Then you got people like me who are willing to toss information at those new if they got questions about a boss. It also helps that guides are popping up on wikis and youtube explaining the boss mechanics that new players can be directed to. The entire japanese playerbase has built itself around helping each other out to learn these kinds of things. Maybe we ought to try emulating that?
Now the problem is you want to remove all RNG. This would mean no traps, no chests, no special mobs, no different floor layouts, no different compositions besides 1 tank 1 healer 2 DPS, because all of those are decided by RNG. In other words it would be a standard dungeon that everyone complains is boring and wanted a change from. Which is in fact one of the most complained about things if you have been paying attention to pre 3.35 threads.
That is what it means to remove RNG from Palace of the Dead. And it quite literally means exactly what I said earlier: the content dies once everyone has finished getting the rewards from it.
You also want to make it uniformly easier, for both parties and solo. More saving more time so that you can farm levels up and be able to ignore a boss's mechanics more easily and if that fails try again.
People only complain about specific instances of RNG related to silver chests, and those instances of RNG are going to be tuned. SE also already said they are putting in a guaranteed upgrade at the floor 50 boss which should help with the intentional wiping/unannounced quitting/people asking to be kicked problem.
We as a community need to also help curb this problem by spreading "Only the exit portal after the boss saves progress! Use the leave command to avoid saving if you did not get an upgrade!" Among the populace. This will also help curb the problem as it spreads farther. Since people apparently do not read the god damn exit portal text.
The Map UI and Character UI are both something aimed at nostalgia given what palace of the dead is based off of, games like Final Fantasy Tactics, Tactics Ogre, the early 16 bit final fantasy games. Its aimed at long time fans of the series like the rest of the game is. Needs some modifications (like the scaling) but does not need a rework.