Ooh you're probably playing the Itch.io version! This one is old and didn't have the volume sliders. They've been implemented in the newest one.
Mmh... I don't know what to say about your keyboard being locked though, I can tab out of the game just fine, but it's a bit worrying for sure. I'll take any info you have! If I can understand what's happening, I might be able to fix it in a future build ^^