What would it take for me to play RO2 again?
Well, the biggest thing would be for the developers to add a game mode, or for someone to make a mod that does the following things:
1) Adds necessary amounts of general weapon sway and more sway after being wounded or low on stamina
2) Removes the extra shift-zoom that makes the game extremely focused on pixel sniping.
3) Adds real consequences for being wounded, such as slower running if shot in the leg, etc etc; and increase bandaging time to somewhat realistic levels. Oh, and totally remove the fact that areas that have been bandaged are invulnerable to bullets. Besides being silly, this is probably to blame for many hit detection issues that players report.
4) Adds realistic weapon limits so that bolt-action rifles make up the majority of the players on the server (like RO1)
5) Gives everyone standard issue equipment such as drum-magazine PPSHs and bayonets, regardless of their rank (would have to be unranked). Again, like RO1.
That pretty much sums it up. I think the game would play out more realistically and more tactically with these kinds of changes. It's important to note that 90% of these are simple tweaks -- not huge game changers, but they would certainly have a dramatically positive impact on gameplay for players who want a more realistic experience.