I realize that it has been a long long while since the mod release, but I'll ask anyway...
1) Will the mod be able to support Windows 10 with the STEAM version? 2) Is the Return to Rook Island Mod significantly different from the vanilla version of FC3 (besides the graphical enhancements)? If not, I just assume use Ziggy;s Mos with the Immersive Sounds Mod. 3) Will the mod interrupt or rather affect coop play? I ask because I bout it for a coop buddy who refuses to use mods and I'll want to be able to coop with them once or twice per week and do single player the remainder of the time.
2) It has a slew of differences, but I focused on adding a lot of graphical changes so as not to just be a repeat of Ziggy's mod. If you want difficulty then Ziggy's mod is the way to go. If you want to encounter new/unusual stuff then try R2RI.
If you really want a DIFFERENT experience try the pirate version (Welcome to Wonderland). That should be quite the change of pace
3) Never (intentionally) touched any of the files for multiplayer or COOP so it shouldn't, but then again I never tested. It ostensibly for single player. If it effects coop in any way no one realized or reported it.
And all this science, I don't understand... It's just my job, five days a week