I took a 3 month break a while ago and came back to a new patch, finished everything added in 2 days and ran Palace of the dead several times till I got bored of it and now I'm taking a short break again. The game is best played in short bursts as the only sustaining aspect of the game is the story and you finish that reaaally quickly.
Glamour is somewhat endgame, but only lasts as long as you remain interested in it and that dies down as you continue with your in game activities. Yeah I look good, but doesn't change anything gameplay wise. 1 month of play time, break, then start again. check to see if your fc members are ok with your play time though.
Making alts won't change anything either btw. After all, this game is linear and doesn't allow innovative thinking in story.
Oh, or try your hand at Role Playing, nver know, you could make your own story but its not for everyone.