Good point about the valve lash. That can really screw up a nicely running machine.
Ditto on the intakes. Watanabetakemasa, I think 2 years is kind of short time to replace intakes too. Depends on a lot of factors, though. Ozone can destroy rubber very, very quickly. On my older G5 which had rubber boots, they would crack and look awful, but they never, ever leaked. Still, it's easy to check out.
J