How hard are daily tournaments and how many can you participate in each day?

So, can I just join as many daily tournaments as I want? I searched for info on the wiki but found nothing.. can I just join every tournament I want? Is it all free?And how difficult are this? (are they full of platinum players or are they easier?)

You can join to all the tournaments you wants for free, you find all level players, but from the second/third match you will usually find decent/strong players (in my experience). Right now when you lose a match your team will be eliminated from the tournament so the numbers of game you are going to play depends a lot on your ability and luck with the tournament matchmaking, but Arena Net has already announced a future change to the tournaments in order to provide more matches for each team.