That is an excellent question and definitely open for discussion! My personal preference is probably for the second option for clarity, although having a year or volume number in there might also be good. The format "Title: Detective Comics (1937)" seems to me like it would cover all the bases pretty well.

For characters, definitely legal names, right? Because characters change codenames, and multiple characters share the same codename all the time, but there is (usually) only one character going by the same legal name. (Although... now I am wondering if the time-displaced X-Men have gone through some special kind of hell dealing with the IRS, Social Security, DMV, voter registration, credit reporting, etc. Oy.)