Never seen a stem like this myself but it's
due to deficiencies and cold nights...
Looks like scale? then theres some aphids... a real spider, and what looks like spider mites LOL
Hmm, are you sure? The plant (from the pictures) looks very healthy and it may just be a pheno expression...
Generally I've found that the genetic for colors is closely related to the genetic that controls flavor.... that boy would be the first thing I used on everything....