J C Lawrence
4) Track builds may be started and/or ended by
upgrading track in another player's track. It is not required that a
track build be traceable through that SAME PLAYER'S track to a city. It
is legal if the track traces back to a city via another player's track.
What exactly does this mean?
It is a rule from AoS:Sun, not AoS: London, and does not make sense without the rest of AoS:Sun's rules.
2. Urbanization can only be done if there is track on the town first. However, then it states, "(track may be built on the town in the same turn it is urbanised)."
How could it be done on the same turn? Urbanization happens before you build your track...
There is no requirement in AoS as to when Urbanisation happens within the turn, or indeed that it happen at all.