I am struggling myself however from what I can tell – you didn’t drop your HST as much as you could do ( I work out it could of been cast 8 times and looking at it further there were two gaps of 1.50 minutes it was not used) . Elemental blast could be cast more – not sure if mana became a problem for you as you cast healing surge a lot but if you did have mana problems you need to increase your elemental blast casts…if it wasn’t then you could drop it as a talent as it is a waste if only used 5 times. I would expect more elemental blasts with more chain heals. If there is nothing to heal I use unleash life to buff the next heal.
Riptide cast seems a bit low – the maximum you could get is about 78 for a 6 min fight however that is casting right when its available however that does not always work. I use a weakaura with a biting noise to make sure I cast it as soon as it is available and do the same for my HST and elemental blast as the cd are so short and can be forgotten for a few seconds.
Your ascendance, spiritlink and healing totem was used only once – however I know for myself I have been facing fights where I seem to only use them once a fight however it does have a negative impact on hps if other healers can use their CD at the maximum rate.
Anyway these are only my opinions and I am not uber yet (however this is what I would be looking at if looking at my own logs).
Look forward to see what others say to give me an idea what else to look for.