I’m going to echo what I said before, as well as what @narthur said here: If you don’t want to commit to doing something every day, don’t commit to doing it every day! Beeminder gives you the option of choosing the frequency of your commitment. Why not use this built-in feature of Beeminder, something that can even be considered on of the primary features of Beeminder, instead of all these workarounds?
If you have goals that are not in the red, then yes, you may well slack on them, not having the concrete deadline demanding that you do them today. That’s not so bad, you want to slack on them. As you say: doing them all would take up some 6 hours of the day, and you don’t really want to do all of them every day. That’s what you said you want! Why not have Beeminder reflect that?