My concern would be for "downtime" and communicating if you are in different star systems.....<snip>....
In-game communication shouldn't be allowed by players in different systems. But, players will communicate between each other no matter what you do in-game with other modes of online commo. In-game it would be nice if communications were determined by what gear you actually pick up. As in if you have a certain TL radio you can communicate with other people on the surface of the planet, not in orbit. Something better and larger gives you communication to orbit or even beyond.
How long does it take in real time to get to another system? Would I the player and/or other players on the same ship be out for around 168 hours due to jump? If not for how long? This of course impacts amount of play time.
I don't see players wanting to wait 168 hours since their ship made a jump. A Traveller mmo would have to make several concessions.
What if jump time was an hour of real time? This would still give a feel that a jump takes a long time so players aren't constantly hopping around spoiling the feel of the Traveller universe. It would give an hour of time for players riding together on a ship to chit chat, explore the ship, trade with each other, train with each other, organize cargo, make plans for the next system....or go eat lunch, use the restroom, make phone calls, run to the store, etc in the real world.
No matter what you do, a reduced trip time would have the effect that friends waiting in another adjacent system could have you arrive in an hour (in this example) of real time instead of 2 weeks. I don't think this would be too much of a problem since mmo players are used to the quickened state of time in-game. Most mmo's will have several night-day cycles in-game for each real day of time. If you are really concerned about time being in sync, perhaps make an hour of real time be a day in-game. Thus, a week in jump would be 7 real hours. This would mean most people would log out after setting themselves for a jump. This could be a good idea also, limiting too much travelling.
Friends Sharing a Ship and Logging
A Traveller mmo would quickly lead to groups of friends crewing a ship. But, what happens when people log out at different times. As in me and three friends own a Scout Ship. I don't play one day, but my friends do. They jump to a nearby system. I log back in the next day to find myself stranded at the starport where I logged out.
A nice solution would be to have players log out in their stateroom aboard a starship. They may not be around for adventuring with friends, but when they log back in they will find themselves aboard their starship no matter where their friends took them.