Phoenix Squad: push to 7* or farm other useful heroes?

That's my opinion alright. Bear in mind that 14 five dot mods for less than 300 cantina energy will drain your bank account to near zero credits.

One of the reasons I'm suggesting phoenix first rather than trying to rescue your credit balance is that I suspect that Palpatine will be early February and you would rather have a seven star team to get a seven star Palpatine than wait a couple of months. Also if you stop starring up your team it will be hard to compete in arena as well.