Nice tune. I like how the song is put together. I thought everything sounded pretty damn good.
Even though it sounds clean, everything kinda of sounds up front to me.
Like its all coming down the center.
I would make 2 mono clarinet tracks and pan them wide and see how it sounds to create some space. Just an idea.
I'm not great at mixing so I can't offer much advice. Creating a really spacious mix is something I've yet to achieve.
But at the end of the day it is YOUR song, so if you like it that way, that's all that matters!
Cheers!