Focus on characters, that can earn you an income of resources:
You will need scoundrels to do the highest tier of credit heist available to you at your level. Lando and Boba are great for this. Chewie is fine at 5*. No need to promote him further. ST Han is often used as well, since he's also required in a hero's journey event.
Try climbing as high as you can in arena for crystals and tokens. Preferably rank 200 or better. It's a little late to start farming phoenix squad. You won't see the big boost in arena, as you would have in early levels. Your best bet for climbing would probably be to either farm a nightsisters team from scratch or to jump on the bandwagon with Palpatine and Vader (you will need 5 rebels of at least 5* to unlock Palpatine). But.... you will need Phoenix at some point to unlock Thrawn and Chimaera, so it won't be wasted, if you farm them instead.
In the fleet arena the milestones are rank 500, 200 and 20. Reach as high as you can. Biggs' x—wing is a must—have, along with FO tie, Imperial Tie and Tie advanced. Farm both pilots and ships. Ahsoka's and Jefi Consular's ships are ok and you already have their pilots. Mace Windu's Endurance is not bad at all as capital ship. Great on offence, though a bit weak in defense. And you have him quire well geared already. Tarkin's Executrix is better, but he is still low level/gear.