Yes glyphs are rare and it should be that way.

I see the problem with the hint part. Usually you have no idea what is the reward, so in case when failing is easy and there is no way to redo the quest you just want to get know how to do it in advance. So you ask other players or (more commonly) consult some page with quest list on the Web.

In light of this findings it seem to me a lot more fair and RP to just try the quest in blind, really try it your way and if it fails you can do it lets say after a week again with some help.

Considering the character creation just to get some specific reward. I think it is better to let each character try more times, than have someone else create character, do some routine work and then delete it.

I have failed few quest recently. Some was because I made mistake, some because there was some misleading information in the scripts. That is ok, it should be possible to fail a quest. It is just a pity that I cannot correct my mistakes and redo the quest. To me it seems really frustrating not to be able to do the quest again and this time be a lot more careful, after all this is only a game.

What I am proposing is to implement a lockout period after which even one time quest, when it was finished unsuccessfully could be retaken.

There will still be a penalty for failing in the need to go all the places again and redo all the work done already. There can even be some penalty from failing, like reducing the Fraction standings.

I don't even think that this will make player more careless when doing quest. It can even encourage
players to be more careful after they do the same quest for third time just because it is proud to do it right. Players even can have more fun as it will prevent them form locking out some quest chains.

I don't see any obvious reason why it would hurt the RP part or anything. Most quests are redone by each player, so there is already some RP problem, but I see no way/need to fix that.