>>56 - 60
Wow, you guys totally fail GR.
>>56
We don't actually know whether any of those are finite. It is true that there are a finite number of particles in the visible universe, but we don't know if there is more outside.
>>58
You're assuming that space has a global positive curvature, which is not proven. A negative or zero curvature would indicate an infnitely large universe. The current data suggests that the world is incredibly close to zero curvature (ie flat).
As you said, a lot depends on the mass density and cosmological constant.
>>59
That is not how time dilation works.
>>60
Time varying metrics can cause things to separate faster than light (eg inflation theories). Light is defined to travel along null geodesics. Any particle that tries to follow photons will still be slower.