This sounds a lot like what Blockland Repository aims to do. Make things automatic in such a way that it will ease the usage for the user.
I'm still working on Blockland Repository, but due to personal matters I haven't been able to work on it for a month. I do have an Alpha up and running, containing registration, upload and download. There's more to it in the background, but I rather not go through it in detail. Due to the cross-reference of forums rule, I cannot post a link, but instead I'll just hint that there's a forum that contains a better detailed log of how's the development is coming along.
I would be happy to have more people on the project. I aim to work along with Blockland Glass someday as we both wants to do this for the community.
It's sad, however, that most mods or projects for Blockland is made by mostly only one person. I'd like to change that by inviting more people to work toward common goals of what we're aiming at. For instance, some people want to upload their save to a site and that site will recognize all bricks, events and colorset in it and then give a list of what add-ons are required to get best result. This is quite easy to accomplish.
I've also done some work on potentially parsing through the add-ons board and automatically indexing all available download links, along with screenshots and descriptions. I feel like that would have a similar focus that would also cover the market for an add-on archive, but at the moment I don't have time to pursue that; maybe after the semester ends.
I had that idea just weeks ago. I haven't come around doing it due to lack of time, but I'd love make or use it as that would make it so much easier to find add-ons that are long lost and forgotten(I just the other day looked at the oldest add-ons at the last pages. Not impressed, but there might be other add-ons that are good to have.).
