Earlier quoted context omitted.
Bob is not the copyright owner. He can't re-licence it to anything. What he can do is re-license a right to use the program, under terms specified by the copyright owner. I've attached extra meaning to c vs s in the word licence, but the definition you used is not the same as parent.
Yes. And if the new copyright owner Eve declares the original license invalid, Bob won't be able to re-licence (or even use the program any longer). Also Alice and Eve could be the same person who just changed her mind.
Referring to the WTFPL author (http://sam.zoy.org/wtfpl/):
Can’t you change the wording? It’s inappropriate / childish /
not corporate-compliant.
What the fuck is not clear in “DO WHAT THE FUCK YOU
WANT TO”? If you do not like the license terms, just
relicense the work under another license.