@ Seth
The short answer is; I don’t think Connections is going to meet your project requirements, sorry. Here’s the long answer…
1. Sorry, this is not possible with Connections or any of its extensions. I’ve had a few other request this as well so it is on my feature request list.
2. Connections does not have a payment gateway feature. Again, this is on my feature request list. Although, I think it might be better to offer extensions for Connections that integrate with the more popular member plugins rather than create one for scratch that users would end up have to make separate purchases. I say this because this request usually comes from those wanting to run member site. Honestly though, at this point, I do not know if integrating with any of the member plugin is possible.
3. Yes. The core templates just use the same layout. The premium templates do have a single view.
4. Correct, no reviews or comments. This is definitely something that will come as an extension. The past 5 months of development of Connections has been very focused on cleaning up is code and making it more extensible so I can add features like this.
I’ve been working on Connections for about 6 years now, starting with knowing nothing. Over the course of that time I’ve become fairly proficient. Future-wise; I will be continuing its development for as long as I can foresee so maybe in the future Connections would be better suited to meet you needs and more.