I'm afraid they are not.
"What would you dare to do if you were not scared?" is correct.
"What would you dare to do if you were not scared of anything?" is correct.
"What would you dare to do if you were not scared to do it?" is correct.
"Likewise" can only be used to refer to similar things, not to opposing things, and it needs to follow the first thing.
This sentence is correct, but of course it means both of them like to stay at home.
"Juan likes to stay at home, and, likewise, so does Maria."
You could use "although" (= "a pesar de") to express your meaning:
"Although Juan likes to stay at home, Maria hates it."