How can I reduce Wear/Tear of a ride? I know age is a factor but are design issues a factor too? I mean, if the ride is too fast/too long or things like that can wear/tear the ride faster?
There's not a lot you can do about this. Even with aging turned off, all rides still accumulate wear and tear, as shown in their maintenance tab. Their "health" line decreases over time. Once it gets down to a certain point, the ride breaks down. When it's repaired, the line goes up somewhat but usually not to full, due to accumulated wear and tear. So next time it will break down sooner because it starts with less "health". The only way to break this cycle is to refurbish the ride, which resets the "health" bar to max.
There's what is probably a bug/exploit with refurbishing, though, that I find quite useful. If you request a refurb while the ride is broken down, before the mechanic starts fixing it, the refurb happens instantly. As soon as the ride is repaired, it's also refurbished. You still pay for it, but it adds no downtime. OTOH, if you request a refurb while the ride is still operational, it can take over a year before the ride opens again. So this seems to be the best counter to wear and tear on an existing ride.
There's also the ride's reliability rating. The lower this is, the faster wear and tear bring down the "health" bar. Thing is, though, you don't have much control over this except with coasters, and then only in a negative way. Coaster reliability comes from limiting the number of trains, the number of cars per train, and the number of "moving parts" in the track (lifts, launchers, and brakes). If you don't go overboard on these, the coaster will have "average" reliability, same as pretty much everything else. You only start running into trouble with coasters if you make like a dark ride that has many slow-downs to see the scenery, then speeding up again. With any sort of normal coaster layout, you'll have "average" reliability. All flat rides AFAIK default to "average" and adding sequences doesn't seem to change that. And with track rides, reliability is simply based on # of cars, and you have to have a LOT of them before reliability suffers.
So really, at the bottom line, apart from designing a coaster with "low" reliability, you have no control over the rate at which wear and tear accumulates , you can't stop it from happening, and the only way to get over it is to refurb the ride.
