Can someone tell me the easiest way to check chain slack and Brake Wear?

 

Chain slack- Just put a ruler next to the chain (in the middle of the swingarm) and pull it up and down. If it goes further than specs, then tighten it.

 

Theres an indicator, on the caliper which points to a range between two lines. Not the easiest or most intuative thing to read.
Its not that bad to just remove the calipers and look things over, plus you know for sure how things are wearing doing it that way.