The only imbalance I see is the diminishing returns from playing in open and with friends.
To complete a pve task in the most efficient way (and efficiency is important for players who can't play 24/7), it must be performed in solo.
Doing kill missions in open will have diminishing returns when facing real players (longer time to kill, more chance of needing to repair, more chance of death). This is also the case for most other mission types, excluding time to kill.
Trying to complete any kill mission in a wing gives diminishing returns, amplified by the size of the wing. I had hoped this wasn't the case and that the reduced time to kill would have made it at least equal. However, this isn't the case, in practice.
I've seen a Dev suggest that he felt it would be fine to allow the community effect to be increased by being in open (whereas the personal reward remains fixed). This would be a decent compromise for considering open player contribution.
However, wing rewards haven't been addressed.
I suggest the following:
1. Rewards in a wing are given to the whole wing, regardless of attacking the target, providing the player is engaged in combat (determined by the player having performed an aggressive act, or had an aggressive act performed on them, within the last 15 seconds) and they are in proximity (within 10km).
This would allow wing players to split their fire without needing to panic and all "tag" every single target just to get a share. Combined fire will be faster for some ships. However, I'm certain the main reason wing rewards are slower is due to the time wasted where every member must target, acquire and "tag" even the smallest, most worthless, targets.
2. Most games with group play provide a bonus to rewards when grouping up. This is exactly to encourage group play over solo (because of the exact same reasons we discuss here, solo is usually, by definition, the fastest way to gain). I think wings should get a bonus. But it should be provided by content designed for different size wings.
3. Being in a wing has a hard coded bonus towards any community goal of power play. Not personal but global. This is to offset the diminishing returns but also to encourage working together. After all, that's what community goals are.