Welcome!
As far as to early to tune, that's an opinion. I did my first diesel with 3000K miles on it. Never had an issue, this one is stock however so it all depends on what "risks" you want to take.
No doubt a tune is beneficial, but loosing that warranty (if something bad happen) would be...
Nope, and not saying I shouldn't. I just haven't in the last three modern trucks... I would love to know if it helps as if I can use anything to prolong the life of my vehicle, I will.
The EcoDiesel has it share of problems, but remember people come here to complain. :)
Many users don't join a forum "just because". Welcome to the site!