If it drives fine, then it's likely to continue driving fine - you obviously drive with 'mechanical sympathy'. so put minimal stress on the clutch and flywheel.

As to 'testing' a clutch, to see if it's slipping ...

One way is quite simple. 30-40mph in 5th, on a nice straight piece of road. Put your foot hard to the accelerator. If the revs rise BEFORE the road speed does (sort of like an old CVT transmission), then you've got clutch slip. If not, then you don't.

Another method (but this does place wear on the clutch and flywheel) is : handbrake on, first gear. NO accelerator. Release clutch very slowly until stall point.

Basically, if the car stalls or is about to stall, then you're fine.

The only thing i would add is does reverse gear engage from rest without "crunching" and the forward gears without baulking (or no more than it always has anyway) ?