Skyblock/skyfactory seems like it'll be a fun (and terrifying) experience!
I have tried to play the modpack myself in SSP, but everytime I loaded up a world it was hardcore, there was no platform, and I plummeted into the void. I gave up on that pretty quickly.
However, this would definitely encourage (if not require) community projects.
For maximum chaos -- uh, fun -- we should all get on at the same time, join a Skype call together, and figure out how we survive. I obviously don't have a lot of experience with Skyfactory (since I kept dying), but I'd be willing to give it a shot!
(Like I kind of mentioned earlier, if we had a Teamspeak, Skype group, or Discord chat, that'd be a great place to talk to each other while ingame.)