[CharlesStevenson]

Welcome aboard.

re the door lock, yes, I believe it's a relatively common issue.

I've had similar on both S40 & V40 & you may well be able to deal with this without having to remove any trim panels or suchlike.

For one I cured it by pulling the pin up with a pair of pliers & that seemed to reset it so it then went up & down with the fob & key.

For the other car, after a while the pin stopped going up & down again, but as the lock was still operating I didn't worry about resetting it again - still working this way today.

Re the low washer fluid light, as Dippydog suggested, it could simply be a sticky sensor. On a 940 we had I removed the container, washed it out & cured the same issue, but on the x40 ... the washer bottle's not as easy to get to.

I can't imagine why a previous owner would have rewired the switch (or elsewhere) to make the rear wiper not work, so that's probably not causing the light to flicker.

Re power, lots of posts on here about getting more out of the diesel engine, however, as yours is now at least 177k (assuming a full service history) you might do better with simply giving it a service & tune up to keep it in good stage-one order.

AFAIK there's no adjustment to the clutch, it simply wears until it goes. Diesel owners on here will be able to suggest possible prices for a replacement etc.

A suggestion: Ebay sell engine code readers & so if yours is showing the Check Engine Light (on the RHS of the dash) then you could pull that data & that might point you to any issues to deal with.

A question: you mention the previous owner removed some bulbs due to some issue, so have you checked that all the dashboard lights come on and go off correctly? It's just that we all know that sometimes owners may try to cover up a fault or two by blanking out warning lights.