Now that we've entered the Core Zone in Theater, I want to give some pointers:
There is no longer a score penalty for repeating stages like in Phase 1, so stick with the hardest stage you can handle every day. The difficulty in the Core ramps up fast. Think of stages 1-3 as easy difficulty, 4-5 (arguably 6) as normal difficulty, and the rest as hard difficulty. Ideally, you want to be able to clear Core stage 8 as frequently as possible once it's unlocked but most players won't get that far. Stage 5 or 6 is where we'll see players falling off due to the higher difficulty.
Even if you can't challenge the harder stages, you can still help out other Commanders by running what you can and contributing your parts to the HOC facility, Fire Position, until it's at Lv.3, then do the same for the fairy point facility, Air Control Center. Having access to all 6 HOC charges and 20 FCP makes the hard stages less difficult.
Don't forget to send out the maximum amount of drones in your scouting bets for those sweet points!