Quick question regarding ticketing from Watford Junction.

The other day I wanted to get to South Kensington from Watford
Junction. TFL suggested taking a Southern service to West Brompton and
District to South Ken. which I did.

Price for a return £5.10 ... BUT, I wasn't sure that I would be
finished early enough to get a Southern train back so to cover myself I
bought a normal £7.10 Watford - London Terminals cd return.

In the end I did take the Southern service both ways - was that allowed
on my ticket?

Also why does the Southern train, stop and turn all it's power off
somewhere around Paddington?

And has anyone noticed that Croxley and Watford West have turned up on
the Silverlink maps in the trains? Have they been there for a while
(listing the infrequent bus service) or is this in preperation for a
train service to resume?

Thanks in advance.

mmlabbd