Well, Heathcliff, though horrible in many ways, was also strong, rugged, extremely masculine, determined, intelligent, passionate, and devoted to his one true love. So there might be something there to name your kid after.
I wouldn't assume that anyone named Heath---Heath, not Heathcliff---was named after him. Does the
Heath in your
Catherine and
Heath sibset have Heathcliff as a full name, or is it just
Heath? If it's just
Heath, I think the parents goofed up if their intent was to name their son after Heathcliff.
I like
Heath, and no, I don't think it will be assumed that you love the character Heathcliff.