>1: The rules for how mex income is split
When first built, the base income of a mex goes 50% to to the owner and 50% evenly split among the team. Over the next five minutes, the split goes to 0% to the owner and 100% split evenly among the team.
>2: The rules for how reclaim income is split
Reclaim is given 100% to the owner of the reclaiming units.
>3: The rules for how overdrive income is split
50% of overdrive income is split evenly among the team. The other 50% is split among the team based on each person's energy contribution. I'm not certain whether it's based on (a) how much energy each person produces, (b) how much energy each person sends to overdrive, or (c) how much overdrive energy each person delivers to mexes, since those three things are not necessarily the same. For the sake of simplicity I would hope it's (b).
To clarify: (a) and (b) could be different if someone has a high energy production but their storage is mostly empty, since how much energy you send to overdrive is based on how full your storage is. Likewise, (b) and (c) could be different if their storage is mostly full but very little of their energy production is tied into the grids, since the amount of energy reaching a mex to overdrive it is limited by the capacity of the power plants that it is connected to.
Also, you didn't ask about this, but it's also important to know how excess metal is handled. If a player is excessing metal, his excess is split evenly among the team. If the entire team is excessing metal, the excess is wasted - or so I assume. There's a "waste" stat in the team metal breakdown when you hover over the resource bars, so I assume that's what that's for; I haven't seen this explicitly stated anywhere.
>4: The rules for how non-excess energy is split
According to GoogleFrog (see
http://springrts.com/phpbb/viewtopic.php?p=514306&sid=902a0752e054298e02f67d84c236851d#p514306 ):
"No one is quite sure how energy sharing works in ZK [..] Energy income is mostly shared"
>5: The rules for how excess energy is split (tied with overdrive)
This I'm not sure about. I assume it works like excess metal - if a player is excessing E it gets split among the rest of the team (this would be nice for someone to confirm). If everyone is excessing E, it will go to overdrive.
Overdrive works like this, in GoogleFrog's words: "the fill proportion of the ally team's total energy storage is the proportion of the ally team's energy income sent to overdrive." So even if nobody on the team is excessing energy, there will still be some energy going to overdrive. If your storage is 25% full, then 25% of your current energy production will be sent to overdrive.
This is just what I've learned by reading public postings. If someone could confirm or correct this (and expand on the open questions) that would be much appreciated.