2010 TXC450 Maintenance Questions

This is the first bike I've owned that did not come with a maintenance manual but rather a USB. I've downloaded the information and according to the competition schedule the first valve check is at 40hr MX or 80hr EN. Am I reading this correctly that if the bike is used for MX it is 40 hours or Enduro 80 hours? Also does the S symbol for the timing chain mean replacement? I'll be doing most of the maintenance myself and plan on lots of fresh oil and clean air filters.
I will not be using the bike for competition but just trail riding so the wear and tear on the bike will be pretty minimal ... also I'm old and slow!:cripple:
Thanks everyone, this is a great site!