Plot line ideas? Well, being locked inside is the standard idea usually. However, the reason it is standard is because the real world part of it is usually boring and you are simply waiting to get back into the game.As well as if it's just a game then why would anyone truly care what happens and if they die. Not as much of an impact and such. Also, for this VRMMORPG, you would need to decide how they play. Do they hook up and basically sleep like SAO or another method. So preferably I think the focus needs to be solely on the game, likely locked inside from the simple limitation of that usually the real world is boring and just the break between getting back to the game unless you have a really good plot plan for it. As for what to focus on inside the game it would depend on what the goal of the game is and how to escape it. (Of course that also depends on if the players know how to escape or not.)