As I wrote in an answer to your previous question, I think a short paper is fairly useless in terms of CV building, so a B+ conference would presumably be more valuable. I don't know your concrete examples, so it's hard for me to tell how these "B+" conferences would appeal to a grading or hiring committee.
Also, is it necessary to emphasize in the CV whether the papers were accepted as a full or short version?
In my opinion it is, if you like being taken seriously. I am currently in a hiring committee, and I see many candidates passively or actively hiding the fact that some of their papers have been in side or short paper tracks rather than at the main conference. This never works, because I will (for all good candidates) actively seek out their best papers to look at them (not necessarily to check if they are full papers, more because I want to see what kind of research the candidate does). If I then find that what I thought was their strongest paper is actually some short paper, my opinion of the candidate deteriorates quickly.
In my experience having your lesser works blend in with your most important papers actually works against you - you presumably have a limited number of papers that you actually want people to check to get an impression of you as a researcher, and having your weak work mingle with your best work is detrimental to this goal. Nowadays I actively highly the <10 best works in my CV, to make sure an evaluator understands which papers I consider to be the best representation of the work I want to do.