Don't worry, you're making perfect sense. Just something about it all feels off to me, know what I mean? Its hard for me to explain over text. Look, go for the dinner since you'll be interacting with a girl at least. When you go just make sure to pay attention to her body language. Learn from it all, gain some insight.
And yes, a girl might still meet if she just wants a random guy friend. Girls don't just want to be friends with girls, same way some guys want female friends. But the issue is that you don't want to put yourself in that pile when you intend to date someone.
Getting to know someone as a friend is not the greatest idea if you want to date. IMO, its only good when dating wasn't mentioned until you've already been friends (ex. you're friends with a girl, years later you both randomly decide to date). But this is the opposite. You're putting yourself in the passive role beforehand.
You don't need to be friends to get to know her because that's what the coffee date is for. People will sometimes say they want to take things slow, but, let me tell you, coffee is slow as fuck. lol.
I need to sleep, I'll remember to reply tomorrow!
TL
R - go for meetup. But use opportunity to analyze her body language, mood, and everything else. Will be very insightful.