The differences I am familiar with are fuel, oil and maint. cost are higher on 4 strokes. Yamaha Sho motor cylinders cannot be repaired. On avg. 4 stroke weight minimally heavier than 2 stroke. Initial purchase cost considerably higher than 2 stroke.
You got 1 out of three right.
Oil and fuel costs are less. Especially on a Yamaha Sho
Sho weighs less than their 2 stroke counter parts. Older ones are heavier. But workhorses.
Cylinders cannot be repaired on a Sho but can on regular 4 strokes. But if you buy a motor based on that you are buying scared. So don't buy it.