Interesting, waiting for IC2 Experimental (and maybe, really maybe GregTech) recipes.
Definitely on the list. I started the project some time ago when IC2 was still in the "classic" versions, and I just updated it to match with the new site. I definitely want to upgrade to IC2-Exp as soon as possible. GregTech (among others) is definitely a mod I would love to add.
have a mod to dump all recipes/items and textures/icons
I've heard that suggestion before. Unfortunately, while I do know Java, it's been a long time, and I've never gotten into making mods. I'd certainly welcome some collaboration, though!
allowing everyone to upload stuff would break it instantly
I've set things up to go through GitHub to avoid that specific problem. Anyone can submit a pull request, and I can deploy to a staging site for testing before releasing the content to the wild. Not quite as easy for people to contribute, but I think it will keep the quality much higher.