Giving a C-MAX a service

Hi all - andanother newbie here seeking plenty of advice! I would describe myself as a reasonably competent home mechanic who has serviced everything from Mk1 Fiesta's to modern Astra's and Scenic's.

I recently acquired a lovely 2005 C-MAX Zetec 1.6 TDCi (110bhp) and I want to give it a service. I particular Iwant to change oil, oil filter, and fuel filter.

Firstly, I discovered the location of the oil filter which is somewhat buried at the nearside end of the engine just above the gearbox. Is there a particular knack to changing it without making an almighty mess??

Secondly, the oil change. The C-MAX has an undershield beneath the engine. Does this need to be dropped completely to get at the sump bung, or is there an easy access point to do this. I'm hoping this is the case as lot of cars with undershields do have simple access points to get at the sump bung.

Thirdly, changing the fuel filter on these seems to be something of a black art. Are these within the scope of a "home mechanic", or are there serious pitfals? Is this job best avoided and left to a professional or main dealer?

And finally: there is a slight build up of gummy black sludge just inside the oil filler cap and rocker cover top. I've extracted most of this using a rag, and when I see this I usually run a flush into the oil and change it soon thereafter. Is puttinga flush into this engine safe enough, or could this cause me additional problems.

Will