Repairable Cores
Neutral core can be repaired like any other neutral object. As panels are repaired, they become under the control of the repairer's team. When all panels are possessed by a team, that core is added to their core count.
Multiple panels can be possessed by multiple teams... you'll have to destroy these panels and repair them to take control of the core. Any panel (neutral or not) can be destroyed, and when a core is destroyed it's gone. It would therefore be possible (?) for a player to "sabotage" a neutral core and prevent it from being under control of a growing power team.
Hostile cores cannot be repaired and basically are treated as obstacles (as neutral cores are now), with the amendment that they can be enabled to regen 10% per x seconds. Maybe a destroyed hostile core can come back to life?
edit: clarity