He should definitely not have a kid. He seems of the opinion that life is painful, and he has wished he had never been born (well, he has wished he had "killed himself when [he] was born", but there's little difference).

To "have a kid" is to create another person who might well wish to never have been born, another person who will have to decide whether or not it is justified to bring kids into this painful world.

I am glad that RMS is so honest about it. Most people cover up their unhappiness.