The GUI has missing buttons for sleeping, unequip and equip buttons mentioned. Is this intentional or left out for now?

Bonus: hose mode does not change upon holding shift and scrolling. (is it meant to be in suck mode only?)

If you enabled curios integration, you won't have buttons. Did you enable curios integration?

yes. I did. what about the sleeping bag button?

Sleeping bag button is available only in placed backpack on the ground

Also you can change hose with Z (Default, change in controls) + scroll (But first you have to assign hose to tank by right click, it resets everytime so make sure one of the tanks is highlighted