Other than the regular service work (oil etc), I will be getting the timing belt and water pump done (it's an 04 plate), and there are a few other things I have been thinking about doing.
Good on you for biting the bullet and getting the timing belt and waterpump done before it breaks. Saved yourself a good five hundred quid there
What would people recommend-pads at a minimum I'd imagine-should I go for the Ferodo or EBC parts? Should I look at getting discs done as well?
Replace pads that are worn, if they're not worn then I'd leave them till they are. They should be worn evenly on each axle, fronts likely a lot more worn than the rear. Ferodo DS2500s for the front, cheap ones on the back (standard, or EBC Greenstuff)
Pollen filter will be replaced I'd day, would an indy be able to do the gas as well or is that a dealer/specialist job?
New gas is ~£50, is it worthwhile? Maybe do it a bit closer to summer to get the most benefit.
Glow plug error
This has been flashing for a few months now-I'm aware that it's no big deal, but I will get it looked at anyway.
Does it start fine? No smoke cloud on start-up? If so, leave it, my JTD reported a glow plug error for 2 years and 30k but always fired up on all cylinders without excessive cranking, and no smoke cloud on start up. I left it.
Front bushes may be worn-should I get anything else done in connection with having the bushes replaced?
Don't change upper arm bushes, change the upper arms if the bushes are worn. The arms are only a bit more expensive to buy+fit than to buy the bushes+fit, but with new arms you get new balljoints too, these can and do collapse. Sods law says if you change the bushes, the balljoints will go and you'll have good bushes in a worn out arm. New ARB droplinks if there is play in the balljoints. 4 droplinks come to about £70, fitting 20 mins a corner for the front, not sure about the rear. Lower arms can have play in the bushes but this is less common than upper arm bush wear.
I wouldn't replace anything that doesn't need replacing, its not anymore labour-efficient to do it on a 52k service than to do it in 6 months time if it needs it then.