Paranoid? No. But it should be an undesirable outcome. You should describe actions with the intent of succeeding without a roll. When a roll is necessary, it should be tense, because as mentioned before, rolls can fail and failure has consequences. That said, you have skills and other proficiencies as failsafes for when you do inevitably end up needing to roll.
This whole concept is just bizarre to me. Rolls are needed whenever anything is in doubt. To treat that as a "failure" condition is just...you're literally saying
using the rules ever, for any reason, is a failure condition. If it is a failure to
need the rules, why are we even playing a game at all?
My answer to the bolded portion is no, that isn’t a problem. First of all, combat is supposed to happen, it’s just something you’re supposed to want to avoid when you can. Second of all, It is ok to have a class whose shtick is helping the party survive when combat does break out despite their best efforts to the contrary. But, additionally, it would be nice if fighters had more abilities that were useful outside of combat.
If it's supposed to happen, it's not a failure state. If it's a failure state, it's not supposed to happen. Like, that's literally what a "failure state" means! If it's
supposed to happen, it is at least in some way intended. If it's a failure state, it occurring means something went wrong.
What else could those words in that combination mean?
In my experience, characters dropping to 0 isn’t all that common after like 4th level. And, yes, when it happens, it should absolutely be time to flee back to town to rest.
In my experience, it is, though I admit I don't have quite as much experience with those levels as I have with the earlier levels. Where characters dropping to 0 (and then outright dying) happened. A lot. Repeatedly. It ruined several games as a result. Hence why I am so skeptical about a rule like this. When four totally different DMs have each caused undesired and campaign-ending TPKs at early levels, yeah, I take rather seriously that death lurks around every corner.
Umm… The game very much has been for something else. Being Big Damn Heroes or whatever is a perfectly valid and fun way to play D&D, but it is far from the only way to play it, either historically or currently. Not knocking it as a playstyle, and I definitely think a house rule like this one is ill-suited to that playstyle. But there are other viable playstyles, including old-school push-your-luck dungeon delves, which a house rule like this is indeed well-suited to.
The bolded bit is covered by the puckish rogues or, for the darkest versions, villain protagonists. Like, that's the whole point of being a murderhobo diving into a murder-hole. You're
supposed to take big risks for big reward. You aren't supposed to respond
with fear to the murder-hole. Constantly running away leads to rather dull gameplay in the Gygaxian dungeon-heist model. Which is why I said what I said.
In combat? Yes, death needs to be a risk. Not necessarily the only risk, but it needs to be there. Unless everyone you fight just wants to take you prisoner.
Let me rephrase:
Why is
random, permanent, irrevocable character death the only form of risk?
I already said death can happen in my game. It hasn't yet (because my players are
extremely cautious...frankly, cautious to a fault
despite my assurances), but it
can happen. The only guarantee I offer is that I won't take away a player's character. If a character dies, then their death will either be an agreement between us, or it will only be temporary, or it can be reversed later but that will require effort from the players.
Neither of those activities are intended to be dangerous.
Rock climbing, football, and being an astronaut are all dangerous. No one looks forward (or, rather,
should look forward) to the possibility of dying from them. But, as stated, it is totally possible that a character could die in my game--they just either won't stay that way, or will pass on because the player thinks that's for the best. The quest to save a friend from death becomes one of the main consequences, which is dramatically more interesting than "welp, guess they're dead and
never getting any resolution about anything ever, what do you want to roll up now?"
So what you're really saying you don't want to play that way. That's fine.
I'm saying the game is fundamentally designed not to be played that way, and stuff needs to be done to adjust it so that it can actually work for that goal. The Fighter being an absolute desert for anything except combat features is one of those things that needs adjustment. Monster design is another.
I legit don't care if people want to use a rule like this or not. I'm solely pointing out that going for a rule like this
without changing anything else to match it is a recipe for upset players and poor experiences.