The chipped off piece won't hurt anything and if not rusted to bad you could have them turned if within spec's. They will always have a ridge after being in service for a while.

Shoe linings sound like they are just over half gone or so but yea replace them.

The clicking you hear is likely to be a broken spring on the side you have yet to take apart.

Replace the hardware with the shoes, the hardware kit comes with all new springs. If you need new self adjusters you need to order them separate, they are not included in the hardware kit. The self adjuster cable is a separate part as well so keep that in mind.

I will run a old drum once turned true again, I only replace them if they are to far "out" or rusted beyond belief. The drums on these trucks are large and tough, made for long service life so use them again if you can.

I buy all my parts from NAPA, they offer quality parts and I've never had a problem with anything from them.