The programming and distribution companies are separate, so there is no
issue with receiving different programmes from different directions.
(all transmitters transmit all TV programmes available on the system)
This is probably the same as in the UK.

With the exception of regional "opt-outs", this is true.

Not really, many of the low powered relays do not carry the full set of
programmes, they only carry the 3 public service multiplexes not the
full set.

See
:http://stakeholders.ofcom.org.uk/binaries/research/tv-research/no3factsheet.pdf

Jeff