[quote=@0Z]
I think there may have been a misunderstanding: I am not referring to any abilities or powers that a character may have, but in possibilities for the players themselves to utilize.

"Fluid time" or "liquid time" refers to entering a single character into multiple topics at once; the time lime remains intact, in that the stories are happening in a specific order for each participating character's history, even if for the players those topics are actually occurring simultaneously in reality.
"Multiverse theory" is similar to the above, only through using different possibilities, or versions, of a single character, setting, or story, and doesn't always mean participating in several topics at a time; this can, but doesn't necessarily, include alternate histories, parallel universes, or retroactive continuity.
[/quote]

That shouldn't be an issue, provided you can ensure that each thread is occurring at a different point in time,otherwise all are assumed to be happening at once.

[quote=@Arawak]
Why a infinite galaxy instead of a galaxy like ours?  Is there any particular reason for this choice?
[/quote]

Most likely in case we decide to expand upon the Galaxy provided interest grows at an adequate rate.