(Note, I am not a developer. When I say things are acknowledged or planned, I am saying it to the best of my recollection of previous developer feedback)
For the interesting platforming stuff.
Not all rooms are randomly generated. There is a chance that a room will use a built-in template. These rooms can provide some very interesting platforming challenges. It's just that there isn't a terribly huge variety of pre-built rooms yet (yes, there is a lot, but not enough to keep things "feeling" fresh over long periods of playtime)
If you head over to the modding forum, they have a room builder tool you can build cool rooms in, submit it, and possibly get it added to the list of possible room templates.
As for the other stuff, some of this is simply room generation glitches (the door places you inside an enemy or crate or something is a known bug). Some of this can be fixed by adding more "patterns" to the room generator, and some of it can be fixed by the already mentioned pre-designed rooms (though their spawn rate might need to go up, and probably rooms for caves need to be added, although they should be built with a different overall shape in mind)
For the upgrades stuff
There is already a post discussing ways to ease the pain of upgrading and specializing. It's just been pointed out that how character death is handled factors into this question as well. You are not the first to note this.
For the monotony of gaining stuff
As has been touched on here, avoiding killing monsters to unlock stuff in favor of explorations was almost certainly taken too far. Maybe there can be a chance to get stuff from monsters, I don't know. Monster drops have also been discussed, but nothing has been implemented yet.
Some of this discussion could be moved to a new thread, or possibly the existing thread about how to make exploration less of a "grind".
However, I would like to touch on something not many people have commented on yet:
I think the issue was that he used the same tactic to defeat the bosses.
He said repeatedly it consisted of shooting off screen at max range.
Boosting difficulty would encourage this tactic even more, I think.
I think his rub overall was that the game was very random yet monotonous. Death could occur quickly and hard yet upgrades are random and don't "build up" as visibly as other games do. On reflection, I admit I get that vibe too after a few hours of play.
This was exactly my problem.
You're right. The game emphases ranged, aimed projectiles heavily. That is fine. But, it doesn't give much in terms of other combat abilities, to either players or enemies.
There are melee spells, but they are oddly expensive right now (already been noted in another thread, MP cost differentiation and balance is another thing on the to-do list), and not terribly much in terms of variety (there are only like, what, 4 melee spells?)
There are arcing spells, and they can work pretty well, but their effective range
tends to be crud.
There is a homing spell, haven't tried it though.
There are "rooted where I am at" AOE spells, but again, lowish variety (not sure about the costs though, haven't tried them much)
There are shield spells, but they are expensive and awkward to use. Thankfully, there is a (by default unbound) keybind that maps to the first shield spell you have, making it much less fiddly to use, but that doesn't fix the cost issue.
I think there is a ranged AOE spell or two, but they are crazy expensive.
And although there are some very good utility/logistics ability/spells already, I agree that there could be more of them.
Anyways, more variety of spells is planned too.
Although adding new tools for combat for players is great, almost everything in the game uses either a weak melee or uses a "straight line" projectile. This sort of hampers variety in battle too. I'd love to see more enemies that use arced projectiles, high level melee attacks, traps, and even defensive abilities
Also, I agree that skelebot's are spammed in too many regions currently, but that is partially due to a lack of variety of enemy types and skelebots are a "placeholder" for regions that have not had their entire "suite" of enemies developed yet. More enemy types is also on the todo list.
So yes, this game still has lots of "kinks" to work out, some quite major. However, I think this game is pretty good even as it is now.
Though, it would be interesting to see a "fly through the rings" mission type.