In article , "Nicolaas Vroom"
writes:

What does a red shift of 6 physical mean.

It means that the universe now is 7 times larger than when the light was
emitted. That is ALL it means, without additional knowledge/

A value we measure NOW from light of a galaxy transmitted
in the past.
Does that value mean we can say anything about the present
of that Galaxy (its present position and speed)
IMO the answer is No. (or very little)
Does it mean that we can say anything about the speed
of this Galaxy in the past ?
Also very little.

If we know the cosmological parameters (from other observations), then
we can calculate any distance and any velocity we want at any time we
want.

The most we can say is that this Galaxy is (was) far away
because the redshift is large, mostly caused by space expansion
A smaller part of the redshift is caused by the peculiar motion of
the Galaxy at the time of transmission

Yes, but at a redshift of 6 this is negligible.