Final Fantasy I - Redux

What does differ from a permanent joining and a temporary one ? I believe the only thing is a presence event bit that is set when the character join permanently so he appears on the airship or in the selection screen. Other than that it's the same command (3F) that is used to put a character in a party... Are you saying that the game nullify the graphics, palette and properties event command when a certain event bit is set for that character?

Edit: What if you remove the character from the party/crew (clearing his presence bit), change his properties and put him back in? Has anyone tried that?

I cannot remember about the properties. I tried before giving gogos sprite and his/her/its name to Gau. Mike and I figured that once gau has joined the party, you cannot give him anyone elses name or sprite. Maybe Mike remembers if the properties can be changed, since I tried this for him in the fire house. It probably has to do with the presence bit as you mentioned...and no, I have not tried the last idea you posted.