Negative effects of Cold Air Intakes and Coilovers?

The only negitive effects would be from how the car was driven. Those upgrades tell me the person likes to go fast and push their car. This can cause premature wear. If the shocks are that old they are likely pretty worn and you would be replacing them soon, you could go back to stock if you desired for around $1000. But going back to a stock intake would be hard as you are likely missing the filter box.