Conjurer - Combat skill rotation question.

[ASnogarD]

I am finding there is a awkward 'hole' in my combat skill rotation, it may be that I am still too low but reading the skills still to be collected and what cross class skills are available I dont see the skill to plug this 'hole'.

I do a Stone I (to apply Heavy) -> Lightning I -> Aero I -> Stone II spam (Fluid if needed to make room, others skills depending).
The issue is there is a wait after Aero I where I cannot apply any skills while waiting for the GCD (2.5 secs) and it makes the combat feel disjointed, is this something I will just need to get used to ?

Combat chains - I heard and seen in some videos other classes getting combat chains, however I havent seen a set of skills with the CNJ...it seems to me the CNJ gets a chain for fighting equal or higher level mobs irrespective of the skills used.
Is the combat chain melee class specific , and the chain I see is a different chain to the chain that highlights specific skills to be used next to gain a chain ?

(added Combat chain paragraph as an edit to by pass limit)