Much Obliged

First of all, I'm a 26 year-old single LDS woman with a blog.  And I have less than 10 posts about dating and/or fashion, so I'm feeling rather obligated to uphold the standards set for me by more popular bloggers.  This post will involve dating.

And, yes, it will be mine.

I have a friend at work who has a son about my age.  He and I were facebook friends before I met her, so when she asked me if I would go out with him, it wasn't as wierd as it could have been.  I gave her my number so she could give it to him.  When I came to work the next day, she asked if he had called me yet.  He hadn't, but it was no big deal to me.  I figured it might take him a couple of days.  He doesn't seem like the kind of guy to play the Game, but he might have (erroneously) thought I am and wanted to wait so as not to appear too eager.  (Important thing about the Game: even if you don't play, you still have to know the rules because you need to be able to spot someone who does play.)

I told myself if he didn't call that night, I'd facebook him and tell me to so I wouldn't have to tell his mom "no" again.  Thankfully I didn't have to.

We've got a date set up and I'm looking forward to it as much as I would any other first date.

But this is the first time I've been set up on a solo date.  (The last was a double, so less pressure.)  There is information about this guy I don't know (and isn't readily available on facebook) and I don't know who to ask.

For example: he and his mom have different last names.  There are perfectly legitimate reasons why that could be.  If I ask his mom, I won't have to ask him.  And if I don't ask him, I give him the opportunity to wonder why I'm not asking him: is it because I already know or because I don't want to know?  But if I do ask him about his siblings, he might wonder why his mom hasn't told me about them when she has clearly told me about him.

Which brings up another sticky point: how much has she told him about me?  (Answer: nothing he couldn't have found out on facebook, but that's not the point.)  From his perspective, he's likely wondering what she's told me about him.  (Answer: nothing I didn't already know, but he doesn't know that.  For all he knows, I know about that time he passed out coming out of the shower.)
But if the purpose of a date is to get to know someone, how fair is it to get that information from a secondary source?  But if it's a known setup, isn't there some sort of expectation that we'll already know things about each other? 

What's your take?