I don't think age has anything to do with it. I know someone who got married at 16, and it worked for her for quite a few years... Now she is on her 2nd husband and significantly happier, but again, has nothing to do with age.... only wisdom (though typically wisdom and age go hand in hand)
He could be the right one, then again he could also not work out. If he has baggage and/or major issues, I do suggest being wary and taking things slowly. He sounds a little intense/ possibly unstable with offering to get you pregnant and take your last name.
ask yourself: can you support a child? do you both have a job? your own place? pay rent/bills? responsible? do you trust him with finances? etc etc, if that all checks out.. go for it !!!! good luck!