Another thought came to mind, part of his power comes from sheer force of will. I recall the Superman #1 issue by John Byrne, who had Supes comment, after hauling a giant piece of earth and building into orbit at the LaGrange point, something to the effect of "It seems as if I can lift heavy objects the same way I fly myself, through sheer force of will."
So I'm thinking at least partially his power is physical as well as mental with even a side of telekinesis - after all when they cloned Superboy he had his "tactile telekinesis" which sort of compensated for some of the real Superman's powers.
So I tink we dispelled the "Women of Kleenex" theory. Now the only real issue is the super sperm fertilzing a human egg... course they both share dna... and the mother's dna patterns would probably help stablize things, it could very well be the reason why Jason was asthmatic and kind of sickly. His body is half Kryptonian and thus probably took a while to get suited to life on Earth. If I recall correctly, Krypton had a slightly different atmopshere (at least according to the comics) and it would take a while for an alien being to adjust to it. So I assume maybe Jason's respiratory issues were due to his super efficient system adapting, growing, changing. But after his powers started to kick in, then his lungs were adapted. We didn't see him wheeze at all after his super-bout of strength. Stress could have helped kick his system into overdrive and gradually accessed his burgeoning power.
A part of me really hates the fact he even exists... "Yeah let's turn Superman into a deadbeat dad. That's really fuckin' great!"