Need Advise On A 2002 Focus 1.8 Tdi With A Few Probs

hi all,

i do have some car mechanical knowledge and will give everything a go but cambelts lol, Ive just bought a 2002 focus with a 1.8 tdi engine? (sure its the 90ps one) it has a few problems which may be easy to fix but thought i would ask the pros before i go all gung-ho and remove everything.

Firstly the central locking doesnt work, ive put a new battery (a cr2032 which i think is correct) but nothing, i read about the re-programming by turning on and of the ignition but i cannot get it to beep as it should? Also if i unlock the drivers door it only opens the drivers door but if i unlock the passenger door it unlocks all except the drivers door.

The fuel gauge is tempermental, one min its on full (which it is as ive tanked it) then the next its as low as it can get with fuel light on. It was on half tank yesturday and went from empty to full to half tank to empty, the bulb is also out behind the gauge (dont know if this is related) would this be clocks or sender? is there any way to test one of the two? how hard is removing the clocks as the bulb will deffo need changing, and how easy is access to the sender unit ?

It has a whiring from the engine i think it may be the aux belt idler pulley but it could as be the bearing what is on the alternator shaft? Does that usually become noisey or would i be correct in thinking its usually the pulley.

It has got an engine oil leak ( for over 3 years as i have previos mots) Its on the front of the engine but from what i can see its quite high up, does any particular seal or gasket go? ive heard about cambelt cover oil leaks but looks worse over to the gearbox side.

the passenger door wont open from the outside - is this just a simple bar fallen of or do fords have adjustments, also how hard of a job is it to remove the doorcards?

sorry its long and theres alot of problems but once these are out the way i can focus (no pun) on the outside and bodywork

regards sam