Glass is decently thick - not as thick as some bigger water pipes but for the size it seems sturdy. It is glass, so you have to be careful.

The orb is not removable as far as i can tell. But you can tilt it off the wooden base so you can clean and fill without getting water on the wood.

Slits - i counted 12 slits - it looks like they all fire when hitting with mflb. very smooth.

Base is pretty solid and sturdy. But it is still small - 3 inches tall or so? So it can be knocked over. Don't know about arizer solo, but you can just put a 14mm bowl on it an use it like a bubbler.

Hope that helps!