Serious question will they be able to have children

He can take human form so I would say yes, since he is basically human in that form (that is why he doesn't harm other living creatures in that form unlike when he is in one of his dragon forms). But that is just my guess ╮(￣▽￣)╭ only time will tell=P

I wanna see mini thems ⁄(⁄ ⁄·⁄ω⁄·⁄ ⁄)⁄

I understand that but what about the child will it have the same power as greed and end up harming her when she/him is in the womb

Hmm, not that is a bit harder to answer. I would still say yes, because even if that will be the case (baby harming her), I have no doubt greed will do something about it(๑•ㅂ•)و✧ And remember that time when mc had a cold/her throat was sore and greed made her drank some water from world tree or some legendary medicine and she begin glowing after drinking it? Maybe she is already not totally human and is possessing some self-healing ability/high vitality or something like that. In any case I am sure greed will make sure mc and the baby would be okayヾ(❀╹◡╹)ﾉ~