I was listening to OP's WIP for the first time when I read your comment. I was going to find out where 1:30 was, but then I heard it right as I read this comment and it was fairly obvious where I was at that point.
Here's something with the banjo that just might help humanization - try studying and emulating banjo playing styles (clawhammer vs finger picked) and how chords are performed with each. This might help a lot here.
From what I know of banjo* (which is next to nothing), clawhammer is usually played alternating between the root of the chord and the rest of the chord (say, on one beat "C" would be played, then the next beat "E" and "G" would be played, and back and forth). Finger picking is more of a broken chord style, each note of the chord is played independently of the others.
*I basically just BSed this paragraph. I have no idea if this is how these styles are played/notated. Take with a grain silo of salt.
I will say though, at 1:30, I like the dynamics you applied to the mallets (Marimba? Definitely not xylophone, unless you wrote this part on the really low end of the xylophone sample's range). I think you could build more off of the mallets, maybe use them for more than just the rhythm and chords. I am not in any way saying don't use them for rhythm+chords, you do this well already and it would be detrimental to take it away at this point, but just to build off of them.
You have some really good ideas, it's just all about execution at this point. What DAW do you use?