Mxsmanic wrote:
If a STAR is marked VISUAL (FUBAR VISUAL APPROACH),

That's not a STAR, it's a charted visual approach.

and shows hand-drawn paths

They are hardly hand drawn.

does that mean it's
intended specifically for VFR, or for both VFR and IFR, or what?

It's got nothing whatsoever to do with VFR. It's a visual IFR
procedure. Do you know what a visual approach is? No you don't
because despite the fact that it will cost you nothing and has been
recommended multiple times, you refuse to bother to do anything
remotely behaving like a real pilot and read the Aeronautical
Information Manual. You'd rather be a leach on society.

I'm
a bit confused by it because I thought all STARs were instrument
approaches.

You're confused in more wayys than this.

At the same time, I've heard ATC clear commercial flights
for the XYZ VISUAL approach, which implies that as long as conditions
permit a visual approach, it's okay for IFR, even though it gives only
landmarks on the ground.

Go look up Visual Approach in the AIM. It explains it fully, what
it's for, when it may be issued.