I did not delve super deep into your logs, but let me share what struck me at first glance.
It looks like you are playing the single target style over the chain heal style. Cool, I prefer that too. The problem I see is that there is a disconnect between your talent choices and your spell breakdown. Let’s ignore for a second which talent in any given row is actually the strongest in sims. If you are set in a play style, you need to choose talents that strengthen that play style. If you want to take the strongest set of talents, you need to adopt a play style that use those talents to maximum effect.
The problem I am seeing is that neither of those is the case here.
I’m looking at Cenarius, since there is almost always healing needed.
Take EST for example, if you are going to choose an active talent over a passive one, you have to make sure you are getting as much value out of it as you can. Yet you only used it once in a 5:45 fight.
Similarly with CBT, it looks to have sat off cooldown quite a bit, and then it didn’t do a ton of healing for the uses it had.
So my advice would be to either take the talents that do the best job amplifying your play style if you are set in your ways OR learn how to use those power talents to their best effect and adapt your play style to do it.
#1 is easy, but won’t give you the results most people want. #2 is harder, but the payoff is worth it.