I'm about to embark on an attempt to refit my bathroom. I'm happy
doing the plumbing myself, but I'd quite like a bit of reassurance
that my plan will work!

There is currently a bath, basin and toilet. I'm going to turn the
bath round, and possibly change the wall the basin backs on to
(although it will stay in the same corner, so this shouldn't be a
major job). The toilet isn't going to move. I'm also planning on
adding a power shower. I don't have to worry about replacing the
toilet, as I'm having my soil stack completely replaced and the guy
who's doing that is going to put the new loo in at the same time.

The basin and bath both have mixer taps (monobloc for the basin), and
all cold water is fed from the rising main. Apparently this is against
building regs or something similar, as there are no double check
valves or similar. Is this correct?

I've got a cold water cistern in the loft and a hot water tank in the
airing cupboard, next to the bathroom. Assuming the previous paragraph
is correct on the cold water front, I was planning on taking a branch
from the cold water feed to the hot water tank and using this to
supply cold water to the bath and basin taps, leaving the toilet on
the rising main. The shower installation instructions say that I
should have a separate 15mm feed from the cold water cistern to the
shower, and a 15mm feed from the hot water tank taken off below the
join to the vent pipe and before any other draws. All sound ok?

The exising wastes are metal and from measuring the diameter appear to
be 1.25" for the basin and 1.5" for the bath. I'm therefore assuming
that if I can cut them off square with a hacksaw (which could be
easier said than done, as they are right against the wall, I can use
standard 32mm and 40mm pushfit connectors to join them onto new
plastic pipes and then use solvent weld/more pushfit depending on how
confident I'm feeling. Does this sound ok? And if so, is it necessary
to strip the paint off the old wastes before I do it?

What's the best way to strip old paint off pipework, especially if
access is limited (why anyone would paint pipework that's right at the
back of the airing cupboard, I have no idea).

Hopefully that all makes sense. All help greatfully received!

Thanks,
Jon