@EdSolo
There are two zetas that you didn't mention that I consider to be top notch. The first is critical for a fully-functioning First Order team, which is Kylo Ren Unmasked's leadership - Merciless Pursuit. The other is Old Ben's Devoted Protector.
I would use the swgoh.gg's ability to filter by faction to go through your teams one by one and assess which ones you really need to focus on (one at a time) so that you can build them up and really make them worthwhile to you across multiple game modes. Using your First Order faction as an example, you've got 3 well-geared, one in the middle (FOE), and the others still at G8 or less. If you were to focus on KRU with gearing for a bit and give him his zeta, and then focus on the FOO and or FOST, you'd have a terrific team for DS TBs, TWs, and better pilots for Ships content. The TIE Silencer is fantastic, so there is no reason not to work on KRU and give him the leadership zeta. First Order should be one of your "core" teams for multiple game modes.
Your Resistance faction is in really good shape. I'd bring Scavenger Rey up to G12, and BB-8 up to G12 plus the Multi-tool (for health steal), so you'd have an even better team for the Sith Raid (as well as the HAAT, and other game modes). These are much more ready than your First Order, though, so less work to do here.
Your Imperial Troopers look really good. None of them are at G12, but they may not need to be. Can they complete the two DS TB special missions that require Troopers (IPD, etc.)? If so, you can probably leave them alone.
As for the rest of your Empire faction, they're in pretty good shape, although you'll want to get your TFP to G12+3 to get him at the fastest possible speed for your Arena, which you've already acknowledged.
You're already working on completing your Nightsisters and have Daka and Talzin's zetas on your list of things to do. I'd keep working on Talia's gearing, since she's so helpful in the Phase 4 STR team. Otherwise, this faction looks like it could do just fine in the various other game modes that you'd use them in (DS TB, TW, Secrets and Shadows, etc.).
Your Phoenix could use a lot of work with gearing. They don't look like they could get your through a LS TB phase 6 combat mission right now, and the Ghost and Phantom are phenomenal ships for your reinforcements (when reinforcement abilities are maxed, especially).
Same thing with your Rogue One toons. They've got a couple LS TB nodes dedicated to them, but yours aren't ready to overcome that challenge. Also Bistan's U-wing and Cassian's U-wing are both fantastic ships (Bistan in the starting lineup and Cassian's from reinforcements), so I'd definitely work on gearing these toons, probably before the Phoenix, actually.
The biggest thing is that you've spread yourself pretty thin with your farming (characters instead of gear), so you've got a boatload of mediocre toons, rather than a core of very powerful squads that can handle what you need them to in one or more specific game modes.
Hope this helped. Would be happy to discuss more via PM if you think there would be additional value.
V