He has about 15 traits via awesomemod's "addtrait" command, but nothing that would be keeping him from asking to go steady.

Okay, I finally figured it out.

I could do a million romantic things like kissing and hugs with the guy, but I never got the option to go steady. Now I've switched to the girl and I can propose going steady. Go figure, right?
then I switch back to the guy, do a few more romantic options, and now I get the option to propose marriage.

Weird bug. Apparently going steady isn't possible as an offer if I play as the guy, but it is as the girl. THEN the guy can propose marriage.

Well the current status is "Love Interest"
So what's my next step?

Asking if single isn't even an option for some bizarre reason.

For some reason I can't have a sim marry his love interest. Or get engaged or anything. Is there a bug in awesomemod that might have something to do with this, or have I simply not reached a certain criteria for something?