[@Ambra] ( I know you may not see this for a while) 

I have a concern about ages: 

Dragons live for "hundreds of years," which implies a limit(otherwise you would say they were immortal, would you not?). And yet they don't age visibly. How do they die, then?

What actually [i]is[/i] the upper limit of age? I'm not sure what is considered an old dragon. I can see that Kaiden is the oldest(whose age is give) but I don't know if he's super old, or just like middle aged. 

Does anyone else have thoughts on the matter, in the mean time?