The little boy playing by the beach is Butch Patrick, who two years later was cast as Eddie Munster on "The Munsters."
This film was unavailable to the public for 40 years, and was generally feared "lost".
This movie was released March 1962. Even though, in this black-and-white movie, John Agar's cracked skin is described as black, in the movie posters his skin is orange. The Marvel comic Fantastic Four #1, drawn by Jack Kirby, was cover dated Nov. 1961, and featured Ben Grimm as the Thing, who had cracked orange skin that looked similar.
Right after John Agar's research scientist character accidentally kills his assistant by touching his arm, he caps off the chemical beaker holding his experimental liquid but puts it in the suitcase so that it's upside down when he grabs the handle to leave, potentially spilling the contents as he goes back to get help from the elderly Doctor.
At 47 minutes, you can see "tagging" on a bridge over pass in Malibu from a gang called "Ambassadors"