[pothole]

Sounds very much like my early '97, which is on 115k, except no gear grind and still on original clutch. Does remind me that I really ought to change to gearbox oil. Mine can be noisy on start up, too, but like yours, only for a moment. Doesn't worry me.

My oil level seems to drop about a bar between changes - change about every 6k miles. Think a lot depends on how many cold starts you do, rather than miles.

Personally, I think these early 2.5s are fairly solid as M96 engines go.

Beyond the bits you mention, would expect the following to be on last legs unless already replaced:

Coils
Rads
Various suspension bushes
Dampers /shocks