Narrowing Down (New Logline: How can I keep players together inside an MMORPG environment without taking away the option to solo?)

Narrowing Down

First off, I could narrow down my log line to: 

'How can I keep players together inside an MMORPG environment without taking away the option to solo?'

What I mean by this is that I intend to somehow design a (more simple) game which uses an environment similar to that found on MMORPGs, in a way that would not split friends apart as is often done in almost every game from this genre.

The next task would be to replicate this MMORPG environment without actually coding it, in order to make it feasible. The key features of an MMORPG I want to replicate are:

• A reasonable number of players can play in the same game world.
• The game world is persistent, thus progression must be saved.
• Players are able to join the game at different times and are able to take actions without waiting for other players to be playing.
• Players can also stop their gaming session at any time, without breaking the game.
• Players can decide to either play alone or together with others. 

So far I have considered two ideas which might allow me to try and replicate the MMORPG environment.

1. A Role playing forum based game. Players would tell me their desired actions and would receive updates on their current situation every so often, allowing them to then tell me their next action.
2. A weekly DnD style, drop-in/drop-out when you please session, where players choose actions in turns and can interact with other players or simply play solo.

With either of these, a small database of sorts would be required in order to keep track of player stats and positions. The said database would only be accessed by me, as I would take the role of the "server". The designed game must be simple enough however, in order to make it manageable by a single person.

Still Over Scoping?

It may be the case that I am currently over scoping. For now all I can do is do research in relation to the problem I wish to tackle, and try to plan the steps that would be required to complete this project. 

Time will tell, soon enough.