The factory recomends to inspect at 110,000 miles. I recomend every 30,000 miles.
they don't need adjusted if they are stock because they are hydralic
If you adjust the valves at 0.08 you can skip adjustment to the second or third oil change othewise you usually have to adjust the valves especially cyl number 3 every oil change which is 3k miles
The error rate is less taht 1%. You should have your valves inspected often.
The smaller the cylinder volume, the more sensitive it is. If it is a 4-stroke, valves needs to be cleaned more often for example. So I vote for th bigger bore.
never
depends on the year.1996 to 1990,some times its low coolant.the coolant grounds the iac,but they do go bad.
every 3000-5000 miles, but your owners manual should tell you exactly what Honda recommends
after 15,000 to 20,000 miles
I believe that is at 105,000 miles
Replace them every 100,000 miles.
Replace it when it becomes cracked or frayed.
have it checked every 3 to 4 years