I'm casting my vote for collaborative solving. Here's my thoughts so far (not going to use spoiler tags since I haven't found a solution yet)
1 - So far we have seen simple substitution, caesar shift (which is the same thing), vigenere with hints at the password, and a combined vigenere/caesar. I'm assuming we're still using some combination of those encoding methods, just with the new twist of not being able to use word length for clues. If we've jumped to something more complicated drw will have to let us know.
2 - Everyone's favorite Golden Girl is probably Betty White? So BETTYWHITE or WHITE could be the codeword, to be added or subtracted to the original message. Or her character name?
3 - I'm assuming the solution is a quote from an 80s song.
4 - Could be substitution on top of vigenere? Or could just be substitution, but then I don't know why we have multiple clues.
5 - Frequency analysis with vigenere only helps if you have a lot of characters. This one is pretty short, so unless there's unique letter combinations popping up I'm not sure how to approach it.
6 - I doubt the characters at the end of the string are a coincidence. Perhaps a mistake, but that can still help us.....