yes, none, yes, marginal.
I did a CPL as an enthusiastic and experienced PPL and Chartered Engineer. I don't regret it for a moment, and added an instructors rating. I've probably recovered the cost of the instructors rating, but not the CPL. Fortunately I'm still happy as an engineer and never really intended to try and become a full time pilot. Weekend instructing however, is a heck of a lot of fun.