I gave those reasons because Yark said the feature is senseless because there are no real reasons to have this feature. I listed reasons which proves him wrong on that account. That the same effects can be done with other measures (often with more implementation effort) does not change that in the least, it is simply irrelevant.
Only your point 5 is relevant as you try to show that the auto-aggro does not achieve a challenge. But you can circumvent it through skill, if you see zombies running at you, run away, restealth and throw stones to kill them. No need to know beforehand what happens. I did try this strategy at insane difficulty and it worked.
well stealth should have its role .. but you probably shouldnt be able sneak kill boss rooms 1 by 1 as long as you 1 shot zombies
like it works now its quite overpowered feature .. and you dont even need any sneak perks to do that auto triggered rooms are weird ... but boss rooms should all wake up once someone die
The devs at TFP created that feature so that POI designers could use it when they think a room should be that way. The designers are surely free to add that flag to a room or not. If a designer thinks some boss zombie should have such a protection he can turn it on, otherwise he won't.
The designer of Grace's "room" did not want to give Grace that protection it seems. Example #1 is still a valid reason why such a feature is implemented and might be used by a designer if he so chooses. Hence the feature is not senseless. That is all I wanted to show by listing those 5 examples.
err last time i seen grace she was passive like normal boar until attacked so its bit hard to tell if she detect you or not
sneak attack isnt problem they can always have high enought health to counter it keeping both advantage of health .. and boss that survive sneak bow shot and have to be finished off
honestly some zombies with 2-5k HP immune to exploding head would be lovely .. even if they just jogged or walked (to prevent .. "omg immortal runner killed me") .. as long as they offer some reward for effort currently we have bears with 2k and demolishers with 800(60%reduction)= realistically 2000 since armor pen doesnt work and bear can still be shot down even with bad ish weapon before he reach player (15 block distance warrior difficulty(halved player damage) .. smg , ak ,sniper rifle,desert vulture)
so nope there isnt any tough boss that can take more than few shots= the only boss like experience is room full of irradiated zombies
This is not done. I don't think it is possible to kill every zombie without the stealth mode easily.
wait what ?

of course you can kill any poi even at 150 days on warrior or higher difficulty easily with no stealth at all
stealth is too slow use it constantly .. but atleast light armor users can sneak on most zombies easily ... atleast if you want shot them with bow or gun ... melee range is usually problematic
so sneak perk isnt .. that great considering real impact
for sneak attack modifier perk 0 or 1 point is enought to 1 shot most zombies base sneak modifier + 200% from bow * 2-3 is usually enought to deal with any feral /walker/cop even on higher difficulties
meaning unperked person with bow is almost as effective as stealth focused sure you wont 1 shot green mom or soldier but those dont appear until +- GS 100 and after that .. you can still quietly kill squishy targets and then deal with few tanky leftovers
tldr unperked = perked in early/mid game and only little bit weaker in late
+ most people use stealth just to land sneak shot on sleeper when they get chancefor free bonus damage .. instead sneaking through poi and you wont wake most sleepers even with guns ... especially silenced
so yeah.. almost everyone use stealth in some way but as small addition to gameplay .. rather than sole focus
Thats an overall constant resistance but i would want something what is 1 time only.
well if i understand it correctly it its immunity to headshot damage by seting modifier to 1x
and that practically prevent " boss" from taking significant damage from first shot because its not sneak damage itself thats OP its sneak damage multiplied by x2 or x3 from headshot leading to insane first hit i cant say i tested specific numbers but with good bow perked sneak damage and agility it can surely go over 1000 damage on first hit 333 damage with negated headshot bonus isnt strong enought to need some "armor mechanic" if boss have 1-2k hp counting in armor