This is correct, but you will lose a small and likely inconsequential amount of CP due to the one CP per uninjured player per session rule.

Yes, but it seems like only in edge cases would the CP be worth more than the proceeds of the sale to the non-league.

it kind of begs a question as to how much 1CP is worth? what monetary value do people place on CP´s? 

I think your approach is likely correct Jason to sell the III/5 type guys.

As you get your team's roster to where you want it to be also have a look at what some of the top teams do (Shepshed, AFC Wimbledon, Kendal Town, Worksop Town) season after season.   

If your roster is small, a case might (?) be made to add 5 CP, get him to III/6, let him become a IV/2 next season, and get a season's worth of CP from him.

Most teams sell just to boost their cash for the new season auctions.

Sigh... notice Al never includes my teams in the "top teams"... such disrespect...

My general take is that I value CP very highly. I will keep an age V player around to get the extra couple of CP and then convert them to BRBs before they retire. I lose a year of BRB that way, but I get extra CP.  But that's for older players who are going to fetch <100k in non league sales. 

For these players Jason references, I would definitely sell at 120k a pop.

But maybe my strategy isn't the best, and the reason I'm not one of the top teams... HMM.

Please take a photo of yourself in the Darth Vader mask Rob then I will add you.  :-)