there's no reason to make things harder for everyone just because a handful of us find things too easy
if people want to use glowing idol, let them. i don't understand this part of your post:
If players are asked to created their own challenges by intentinally gimping themselves and not using all of their tools, the satisfaction of overcoming those challenges is lost.
this is markedly false. people make up their own challenges in gaming all the time (speedruns for example), and succeeding at these things is no less satisfying than any other achievement in video games. personally, i don't use glowing idol of rebirth and i don't use morning person either, mainly because i try not to die at all but also because they make a game i've beaten many times on its hardest difficulty a little too easy for my taste. however, none of this means the game needs to be changed
i do, however, support the idea of an even harder difficulty being added, and i think this forum is full of good ideas (many of which are outlined in your post) that could result in a really good extra challenging game mode. restricting certain things (glowing idol for example), adding more enemies, giving enemies access to more skills, etc. are all ways that could make already tough fights even tougher
tl;dr, i think your suggestions are good, but i don't agree with removing or nerfing things from the base game for the sake of difficulty. lots of people consider games like these a huge challenge, and removing the things that could give them the edge because some of us think they're too strong is ultimately unfair. on the other hand, removing or changing these things in an extra hard difficulty would work towards satisfying the players who find the game too easy, while not affecting players who find the game challenging as it is
