Answer to Question 1
1.4 solar masses is the Chandrasekhar Limit. While dwarfs less massive than Chandrasekhar's Limit can remain stable by gravitational contraction for billions of years; above that limit, electron degeneracy will fail to stop the contraction, and the white dwarf will blow up as a Type I supernova, or collapse to a neutron star in a Type II supernova.
Answer to Question 2
FALSE