Cylinder Scoring

That serious!

That is not good at all. Sorry to be the bearer of bad news.

Same here. I assume it wouldn't be any harder than a P-tek. You will have additional electronic components. Its still a mono-block.

Lack of oil or water ingestion.

That looks like it is from water ingestion. Is it on the intake side? If it has compression and it runs, I would ride it. I had similar scuffs from sucking snow through the turbo and rode the sled to 2500 miles. It may last, or you may start losing compression. Rideability depends on compression. Nikasil can look rough and not be that bad to the touch.

I am not there to see everything in person to say much more than I have said. To me, if the compression is good ride it. The piston will mirror the cylinder. If it was bad seize, it would likely test lower compression and/or have other signs of damage in the skirts or ringlands. There could be several reasons why a sled would lose power and be hard to start like you described. I have seen electrical issues display similar symptoms. Your description isn't enough to say a spring ride caused the scuffing.

Also, I would not port a turbo motor. I know a lot of engine builders who spent a lot of R and D time and money researching it. Their conclusion was the performance gains and losses do not justify the cost. Turbo engines behave differently and benefit from lower port timing and different port velocities than an NA motors. However, if you want to do it. Make sure to find someone who has real data to back up their claims. Otherwise, you may spend a lot of money for without realizing useable HP and instead get some peak number you see for 5% of your riding.