Hi Charlie.
I actually think you are quite close to the original interpretation, which is great.
However you are doing a few things that work against you. Two specifically, you are attacking the verses with a glissando, a scoop. For example on haaaaAH way run, and ciiiiiIIIIrcus life (you begin on a lower pitch and bring it up). Focus as much as you can on attacking the note right on its head, not bellow, not above.
And also, timming. There are key spots that you are attacking on the upbeat, and that also works against you. A simple example: Right on the beginning, highway RUN. In there, if you take care so that the phrasing makes RUN sits right on the beat with the keys, it will sound killer. On the next phrase on the same idea, "Restless HEART" same problem happens.
You do however make it precisely on "Circus LIFE" and "Through space and TIME".
These two things do not require anything that you are not doing already on your voice, and I think will improve the quality a lot.
I, personaly, notice that its just my taste, also did not like the super high note on the ending, but its a matter of choice. The rest of the higher section is killer as it is.
I hope it helps man.
GL!