wertified

Cap is not just a peak of human, cause if you take a measure of his feats of strengths all of which is impossible to be done by a normal human being. He can bench press 1200lbs consistently, can run at 48kph and an occasion which states during the duress mile he sprinted 1.6 kilometers in 73 seconds. One more thing Spiderman's reflexes is same as Cap, they can evade simultaneous ballistic attacks from multiple attackers. Cap senses is in the highest possible limits of human potential. It is also stated he is able to dodge bullets because he sees faster than them. These are not just at the peak of human potential Cap is already a super human, his abnormalities would have been that of HULK, when Banner's dad recreated the Super Soldier serum which eventually failed.

Actually they (steve and natasha) have a relationship. Its more likely according to the multiverses, they never did have a relationship in Earth616 but in Earth-555326 they did have a son, James Rogers.