Returning player, hoarded account needs advice

Fleet entry isn't as important because there are only 2k people per shard and you can't manipulate like you can squad without waiting days at level 59 which would sabotage squad.

It's not just what gear every character needs that's important. What's more important is which gear you end up with 100s of because they are in a node that you farm foe something else.

I'm not saying is an exhaustive list. I just looked at a few characters between gear 8-10 and made a list of what they needed that was available in sections 1-3 that I didn't have hundreds of that I would actually have to farm to get. I'm not sure what sections of the battles you have open to you.