Re: 1-5 to 6th edition
When I started (an now aborted project) to convert a number of old Champions characters over to 5E (none of which were mine I should add) I decided to convert them as written. So of the character has a Force Field in his MP, I left it there and adjusted things to make it fit.
The question is, are you simply trying to make them into 6E representations of their initial appearance, or are you trying for a full update to 6E. In case of the former, leave everything as written (which is "b" in your list above), in the case of the latter, do whatever seem proper to make a "better" (more efficient, more logical, or well-rounded) character.