This would never ever be a risk. You cannot get HIV from causal contact, hence why it is classified as an "STD", and a blood borne disease. This is true regardless of cuts, breaks in the skin being present.
Extremely unlikely.
you didn't scratch to a point where you bled
You're more than likely OK.
it takes immense quantities of blood or fluid exchange for an infection to occur.
what if he had blood or semen on his hands?