Chests
 

Have a few questions about chests:

1. Are they shared (if someone loots it another person has to wait for a respawn before looting it)?
2. Are they relootable or you can loot a chest located at a specific position only single time?
3. Is the reward random or you get a specific items from a specific chest?

Thanks in advance! I'm sort of a completist so I'm wondering if I have any reasons to hunt for every single chest. The other possible reason for hunting is getting gear which boosts my character as soon as possible.

1. They are shared, so if someone loots it before you get a chance it disappears.
2. As far as I know you can keep coming back for chests when they respawn. I haven't looked into the respawn time though.
3. They look random to me based on zone level and difficulty of the lock.

Oh, thank you! No hunting though... :C

I have one more tiny question: are those treasure maps required to be able to see the marked "treasure"? Or they are completely useless for those who are aware of esohead maps?

You need to have the map for it's interactable AFAIK

So looting the treasure consumes the map, right? And is it possible to acquire the same map once again or these treasures can be looted only once?

Correct.
No idea about the other question.

Multiple Maps
 

It is possible to have more than one copy of the same map, although I am not sure they respawn, but rather are random. I also was able to have one of my characters place the map in the Bank for another to use, which effectively allowed for double usage. Ok, this was all in the Betas. I have no idea what the game will allow.:D