Great post! I can certainly sympathize. My simple thoughts (especially on using skills in general):
First, there's all this "me-tooism" going on, where EVERYBODY wants to roll to see if they can read the inscription. I know some GMs solve this by saying that only one person gets to roll, calling that the best attempt, and in a lot of games whoever has the highest skill becomes the point person. But in games where rolling is a chance to advance, everybody wants to be that person.
My first thought is I would rather have this problem then a bunch of board players on their phones not paying attention, haha. Back to the problem though:
No matter the system, when I use skills, I:
First, decide if it's worth a roll. Is success or failure important to the session? If it's not, just make a ruling on success/failure. This usually means the task wasn't a challenge though, so no improvement possible. Maybe next time.
Second, decide who could reasonable help. Maybe there's a few characters that have no chance. Tell them no and let a few players feel special for a moment.
Third, decide how much it helps. Use the appropriate "levers" to figure out how much easier the task is now. Usually, by letting everyone get a chance to roll or making the roll numerically easier via bonuses or lowering target number.
So in this Dragonborn case, if the inscription was sufficiently challenging, I would let everyone who had a shot of reading the inscription a roll; d20 for the main, d8s for the helpers. 1 or 20 or the main gives everyone a mark and chance to progress.
Second, the players aren't doing anything. Why are they rolling to see if they spot the hidden door? Because they happened to walk past it. There's no thoughtfulness, no planning, no risk-taking. Finding the door isn't a reward for good game-play, unless you count "putting points into Awareness" as good game play. Which I don't. Or, at least, if the skill in RPGs comes down to knowing how to build a character, I'm not really interested.
For a lot of players, this is preferred to cut down on the "boring poking around" parts of dungeon crawling. Sounds like you're like me though and enjoy it, so certainly change this aspect up. Make the act of finding hidden objects not automatic, but intentional. Listen to their description, decide how difficult it would be given their description, then award the appropriate Boons/Banes as you see fit.
Third, if nobody succeeds they know they missed something, so then they start poking around really carefully, even looking in exactly the right spot. So...I'm supposed to give them their reward, even though they failed the skill roll, because the roll itself signaled they should stay in that spot searching for something until they click the right pixel?
I would not allow rerolls. Meta wise, yeah, they know they missed something, but their characters sure didn't, haha. Players get a change to explain what they are looking for and how, then one roll is made. If they didn't specify looking at all, then no roll is made at all. Keep in mind auto success and failure depending on the description too.
Oh, and then there's lock-picking and trap-disabling. The dungeon had several instances (at least three) where the key to a lock was hidden in another part of the dungeon. Which is a pretty standard video game trope, but when you have a sleight-of-hand skill, and an incentive to use skills, eventually all the locks get picked. Not only was there no problem solving, planning, or other trade-offs, just dice rolling, but the presumed purpose of the locks and keys...getting them to explore the other parts of the dungeon...wasn't actually achieved.
There is nothing wrong with letting players know that there are two kinds of doors in your games: generic ones that use generic silver keys and specialized ones that use specialized keys. Specialized doors can't be picked, period. If you're feeling generous, it can be attempted, but with Banes.
One final thought specific to Dragonbane:
Let 1 and 20 determine marks as usual, but also as a GM, let them mark their skill in times you feel like they really derserve it too. Like being clever enough in their description to not need one or pulling off a really important task. Heck, I'd even let them do it for an elaborate description that was just flat out disasterous if they still put in the effort (since this is effectively rolling a 1).