Hi Joe,
Here's my low down on your questions. Personal experiences only, your mileage may vary etc.
New plugs - I wouldn't bother unless there's a problem. Didn't change mine for 45k miles and they were still fine. Like new in fact.
Carbs balanced - With a Morgan Carbtune they're a doddle to set. Don't need doing often either.
Engine oil and filter change - Doddle. Use semi synthetic. Various people have had excessive oil burning (me) and slippy clutches with fully synthetic. (Other makes seem quite fine on it, however. I might have been unlucky)
Air filter clean (may swap to a K&N, not for power but more that its reusable?) Went 45k on the original air filter. At 20k, I'd just blow it out and save your money.
New brake fluid (hopefully braided hoses) After 11 years I changed to braided and noticed very little difference in feel. Save your money unless they're in a dire state and get the callipers and pistons immaculately clean instead. Bigger difference than braided hoses after a winter like we've just had.
Want to fit a scottoiler, money allowing - 35k out of a chain with one of those is achievable. Worth the money, but jeez, they make cleaning the bike a pain. Wouldn't be without one though.
General check of hoses and cables - always a good idea. Had to change the radiator hose than runs near the front sprocket because after years of chain filth it was starting to go last year.
Check and greasing of bearings and pivot points - 103k on the original monoshock and swingarm bearings for me. They're like new even now. Need very little doing to them. I think I've only greased them a couple of times in 12 winters and all those miles. Odd thing is that as new Fazers have half centimetre of play if you lift the rear wheel, but it's quite normal and doesn't get worse with age. The linkages are a doddle to take out too. 30 minute job unless the silencer's seized in place. In fact, even taking the swingarm out only takes 45 mins.
As Capt said, the EXUP needs regular attention to keep it happy. It's just about the only weak point apart from the finish which is a problem due to corrosion but the rest of the bike just seems to go on for ever. It's like Robert DeNiro in Cape Fear - just keeps coming back for more!
Some very dodgy looking download sites for Fazer Service Manuals. I grabbed a copy a long time ago and I think it was from here. But if you're on a PC, virus check it.
http://www.carlsalter.com/yamaha-service-manuals.aspHandy site eh? Incidentally, how's your fuel economy at the moment - mines back up to where it should be now that I've fixed my EXUP and the weather's warmed up - 45 ish to the gallon and over 160 to reserve. Has yours improved?