Red hair typically indicates a fiery, fierce, wild character with a temper, which naturally fits "the Dragon". Likely giants or titans also often have red hair in stories. Of course the red hair also helped as an obvious sign to show that Rand is different, especially in the beginning of the series (together with his height and his blue-gray eyes). Thus, I would say it makes sense.

As for other fictional heroes, e.g. the main character in the first Dragonlance saga, the half-elven Tanis has red hair. Also Kvothe, the protagonist in The Kingkiller Chronicles is red-haired. Probably one could find some more.