think its more to do with your definition of soul mate I guess.
My definition is that you and him, or her i guess, do EVERYTHING together, that ot me includes sex, so to me, my answer would be no, you can't be soul mates with someone who doesn't love you.
My closest 'soulmate' besides my OH...we have known each other so long that we know what we are both thinking...we know when we're putting a front on...we know when the other is pretending to be ok...we can finish each others sentences...we can argue and never fall out...we can say things to each other that even my OH wouldn't dare to say to me...
We would make the perfect couple...except we don't fancy each other.
It's lovely to have Molly....except it for what it is though. Two people that get on very very well. I love him because of the amount of time we've been friends.
I think (and indeed I know) that you can have close supportive friendships with people of the opposite sex without any romantic involvement. For a long time my best friend was a bloke - and my OH and his accept that we are still extremely good friends and there for each other if we are needed. We are very lucky. Soulmates, though? - I think that has an implication of a closer relationship, IMO.
He's perfect in everyway that matters to me, except he doesn't love me (I don't think), but we get on so well it's as if I don't care and still want to be friends.
You're basically saying you do fancy him, and would have a relationship if he asked you. So basically its not "soul mates", its someone you fancy and have alot in common with, but he doesn't fancy you.