1. I've found the copy of ai.qst uploaded by Joe123 near the end of the release topic. I imagine it's the same as Prince's original release, but if you have an earlier one that'd be great.
2. Is your copy of the Adventure Tileset different from the one in the database? Also, did Freedom ever finish Robin Hood? I don't remember his doing so. Can't remember which version.
3-4. I'll PM NoeL. I think Sheik should have the MC stuff, so I'll message him too, but I'm not sure.
5. Here's the thread in which ElLibertador released Parade of the Numbers; all the pictures have been deleted, however, so I'm not sure how helpful it'll be.
I've found the copy of Captain Magenta's stuff that Furion/Lord Ike/Astromeow/Marco worked on and made more useable, but if you have Captain Magenta's initial release that'd be great. It looks like this:
1. That is also the one I have..
at least, that's what I'd say if I could actually find it. EDIT: Found it. You can check it out. I started to draw one screen, but it seems identical to his release. [link] I do vaguely remember that thread (more accurately, I remember how hyped people were when he released them), even though I didn't post it in, so that's more than likely the version I would have had. I'm going through my old ZC crap now, but if I find it, I'll still post it for you so you can compare.
2. Yes, I forgot Freedom actually released the tileset. It's even the first set in the DB >.>. As far as I know, he did not finish Adventures of Robin Hood. I remember he got really pissed, and basically quit ZC cause of bugs and whatnot. It was a different time indeed. I will also keep looking for the demo. I tracked down a post of Freedom's, since he had a site with a lot of his stuff in his sig, but sadly, the page has been lost to the ravages of time. He hasn't been online since 2012 (not to be dark, but does anyone know if he is still alive? I know he was fairly old for a ZC user) so getting a hold of him is probably not happening. He was usually nice about this stuff though, in contrast to some of his gruffness, he gave me the password for Search for Elise cause I wanted to use the tileset, but that never happened cause it is complex af. EDIT: Found the demo. It is passworded. FWIW, I tried the password he gave me for SFE, but it didn't work.
3-4. Yeah, iirc, again Sheik has done a lot of stuff with the BSMC package, which, I think Linkus put together, but I know it has changed hands a number of times.
I still got nothin' for the last two though. Sorry.
Also related, I figured I'd drop this here. A while back, when ZC was transitioning to 2.11+, ShadowTiger, and a few others were working on a rather ambitious group quest known as "NeoFirst". It was a collab project, that I don't think ever got finished. I have a version of that, but I'm not at all sure how current it is. It's from an old 2.11 beta, but it opens up in 2.50.2. It might not be usable today, but it's worth mentioning here.