Those robots will never fit inside a standard sized Suicide Booth so chances are they'll work in those factories until their little robot arms fall off
Which will significantly reduce their suicide success rate. Problem solved!
I laughed, anyway.
Typically when a song is remixed or sampled, the copyright holders have given permission and are getting royalties.
I don't have figures, but no, not for the notable ones at least.
The artists and marketing guys know and encourage remixing, but it's not normally a contract situation. That often leads to conflicts with the RIAA in their 'super SWAT team' form. See this for example.