Bananaz, your "barrage of questions, is not seen as a negative but interesting for those on here who are following this thread.
That first smokey start up when I first looked at the car with a view to purchasing it was followed through out every cold start up. When it was warm it would be reduced, but still there would be a little smoke.
When hot the "dreaded" idling noise was always there, sometimes quieter, but there.
Now oil consumption, this was a little harder to use as a reason for a rebuild. I had oil leaking from the RMS. area, and all the other " normal" area's that a porsche engine has wet patches. It therefore did use oil, 750ml per 1000 miles.
I would rule out fouled plugs as the reason for running on 5 cylinders, there were two very poor cylinders that burnt oil, and both on the same bank. Further more, the coil pack shields were missing on the same side, and the coil packs were cracked and starting to "delaminate" this was their down fall, and therefore missing on one cylinder.
I am guessing that your questions are specific to your findings of your own car, and my answers will only go to prove what you may already have thought.
Interesting findings on the bearings!
My car is new to me, and I specifically looked for a car without any obvious bore-scoring symptoms. One car that I looked at with 115k miles was very noisy at hot idle. It sounded a bit like an exhaust manifold leak but was piston slap. I paid to have it borescoped and it confirmed my suspicions. The service manager of the specialist that scoped the car assessed it at 7/10 progression. At that point, more than one piston would have completely shed the ferrite skirt coating and be galling against the bore itself.
The car I ended up buying has 143k miles. What could go wrong lol? There is fairly recent IMS/RMS Clutch/Flywheel work, but other than that, the engine appears original. The usual signs of scored cylinders (blackened left tailpipe, puffs of smoke from cold, noisy hot idle, high oil consumption, plug fouling) are absent. It's too early to comment on oil consumption per 1k miles, but so far it has run nicely for the first 400 miles or so and the oil pressure is perfect.
The funny thing about bore scoring is that it it occurs at any mileage. It's not the case that if you get past a certain mileage that you therefore have a good'un and that you are safe.
It's also not the case that if you buy a genuine low-mileage example that you're safe either. Either of these two sorts of cars can have scoring issues without fear or favour.
The crazy thing about the UK market for the 996 C4S is that it values cars based mainly on mileage. Other factors such as transmission, colour, owners, and detailed history are also important - but mileage is the key factor influencing price.
A car with 150k can be had for 17+ grand whereas a car with under 50k can fetch 32+ grand at a dealer. At both ends of this spectrum you can find well maintained, ready to go examples.
The killer question: Which one is least likely to have bore-scoring?
The killer answer: Nobody can tell you, it's fairly random! All you can do is get a borescope on any car you are serious about or buy from an indie that does this for you.
With that in mind I went in privately at the lower price point, figuring the same as the OP - that if I ever have to rebuild the engine - at least I've left the most financial headroom possible.
All engines will need rebuilding at some point. To get there, you only need to keep driving them!!
There are a lot of scored cars out there, and many come up for sale. The rebuild cost is such that many owners elect to cut their losses and trade out of the car. These cars then pop up in the non-specialist dealer network all the time, many of whom don't even know there is an issue with them. Caveat emptor and buy them at the right price like the OP.
