I would go all the way with GS to 7* until you can 3 star the health mod challenge - maybe take a day or two getting some five star mods.
Good question on ahsoka - I'm not sure but I did QGJ before Ahsoka (as I farmed QGJ before Boba).
For energy, much of the gear you need could be in relevant hard nodes so do that then. I would think about JKA, Ahsoka, Chewie (until 5*), and maybe Rey & JC (I see you have Boba already). This really depends on what you want to focus on though
Max sure you refresh twice a day as a min