Questions on where i can be bound

[Kragar]

So I tried to search for the answer to this, but the search pared my question down to 'binding'...ugh.
1) can only someone in group with you bind you somewhere?
2) can you be bound somewhere not in a city? like those karanas are a long way away from qeynos, man! A list or link to where you can/cannot bind would be awesome.
3) can casters who can't bind themselves yet be bound in more areas than melee characters?