These are cases of what English learners would call "mixed conditionals". In this case, the "si" (if) clause refers to something that happened in the past, so it uses pluscuamperfecto de subjuntivo. The "then" clause refers to something that happens now so it uses the simple conditional. Compare:
Si Cándido no hubiera caído del árbol, ahora no estaría en el hospital
(if Cándido had not fallen from the tree, he would not be in hospital now)
with
Si Cándido no hubiera caído del árbol, no se habría roto una pierna.
(If Cándido had not fallen from the tree, he would not have broken his leg).
In the first example, the "then" clause is happening now, so we use the simple conditional (no estaría en el hospital). In the second example (which would be called a third conditional in English grammar), the "then" clause happens in the past, so we use the perfect conditional (no se habría roto una pierna).
For your second sentence, both
Si Feliciano no huberia nacido un martes y trece, tendría más suerte en la vida
(If Feliciano had not been born on a Tuesday the 13th, he would be luckier in life).
and
Si Feliciano no huberia nacido un martes y trece, habría tenido más suerte en la vida
(If Feliciano had not been born on a Tuesday the 13th, he would have been luckier in life).
are valid, though again with different meaning. The first sentence indicates that "not being lucky (enough) in life" is an ongoing state, while the second sentence emphasizes that Feliciano was not lucky enough in the past (and could have been luckier).
Note that, helpfully, the English translations of the sentences also use different tenses in the two types of conditionals.