When you’re solo, if you’re the only person to damage an opponent, you usually (see down below for possible considerations) get all the AP.
If you are part of a group, then for every member of the group (even if they didn’t participate in the killing or healing), as long as they are in range, the AP will be split with the members of the group See the spreadsheet linked above for more details. There is a balance to be found for making AP, and I’ve always preferred groups of 6 to 12 – as beyond that the AP is too diluted.
yes the game rewards you ap the most in groups of 8-12 i believe.
sorry to hear your emp push failed. dont give up though!