It's not quite paranoia as much as caution. I've never been a dub. I don't particularly go for some mega churches. You can't possibly know 10,000 members. The house churches of Acts were much more of a community.
That said, I don't think everyone who invites you to church is being disingenuous about wanting to be your friend. I invite friends or family to my church who show an interest, have mentioned they're looking for a church, or if we're having a special event. It's an open invitation and they're welcome anytime. I don't do this to gain membership for my church but because I attend there (I've picked it from among weeds and can give some sort of personal recommendation). It's not perfect because we're all imperfect but it's doctrinally sound and we're all striving to be more like Christ. I simply don't know that about other churches.
If I extend an invitation and they don't come, I don't stop talking to them. That's a HUGE difference from JWs. My churchgoing friends are the same. I'll give an example.
-When I moved, I was looking for a new church. I visited many I heard about and one on the invitation of a friend. I went once and it wasn't my scene for whatever reason. We're still friends. I'm going to her son's birthday next month.
-I made friends with someone who goes to another church. She invited me but I haven't gone because I feel I'm at my church for a purpose. There are no hard feelings. I'm seeing her tonight in fact. It's not about competition in my mind. I'm glad worship is going on in other parts of the city.
Visit churches as you feel comfortable and take your time. They're not all the same. And there's nothing wrong with just continuing your Bible study in a small group. Church should grow you as a Christian. You don't need a building for that.