I have been designing for 50 years, bearings are a specific field and I have used bearings in that time, but I am not an expert on bearings. When I had to use bearings I got expertise from a bearing manufacturers rep. and picked his brains, as that was his job.

From what I have found on the web, I would not be using stainless steel bearings, people seem to be going for them because of rust. The problem with SS is that it can only take 80-85% of the load of a steel bearing. The RS seal is not recomended at the higher revs of the basic seal,it is rubber and fails at these speeds. It is better to use Z or v types, but I would not use this S.Steel bearing at all no matter what seal.
The result here would be it would fail sooner but look nice and shiny, not a strong reason to go to SS.

All the rust in the first thread may have caused it to fail but I doubt it. My first thought here would have been what caused the rust and solve that problem first.

My immediate solution would be to use two bearings not one and use a longer stud if required.

I cannot find a solid answer on the use of ceramic bearigs, they look like Gods gift but can they take the load as well. Ceramics come in three types, all ceramic, and hybrids; ceramic ***** with races of steel and ceramic for ***** and one race with the other race of steel.

My basic question is why increase the crank pulley diameter thereby increasing the speed and stress on every compoonent attached to the belt
Why not decrease the pulley sizes on those components you want to speed up, this could have led to the idler pulley being increased in size.
For example how fast can a water pump spin before it gets inefficient?Surely spinning the alternator faster than is needed wastes power?
Not the cheapest initial cost but? ......