How about this. The further AWAY you choose you starting position from metal spots, the more starting metal you get. This way there wont be so much fighting for the "best" starting positions in large teamgames. Players can choose "unusual" starting positions which leads to more variety and awesomeness.

What would be the formula between distance to metal and starting position?

Uhh... where have you been? Mex sharing has been an option since 27/4/2009 (r4502) and was enabled for the vast majority of games. Sharing has been mandatory since 11/2/2010 (r6786). It's mandatory because OD was rewritten for pylons and no one did not use communism, it's a lot simpler to support 1 system.

Your suggestion fixes a non-existent problem. All mex income is equal so mexes do not make for the best spots.This is what has happened already!

In fact, I find that the problem is the reverse - too many teams have "parastic" players who build neither E nor M

yes thats annoying. but you can not blame new players, they might think they are doing ok but then in another game they do not have as much shared ress from the team and their buildorder fails.
it happens to me too because in other games i only make more e when i am close to stalling. in ca that does not work.
imo in > 3vs3 it gets hard to see the result of your eco efforts like making a geo, reclaiming etc

Reclaiming all goes into your kitty, and it is the hallmark of a good player to have a large reclaim fleet.

Most energy goes into overdrive. The problem with this is its a little invisible.

And no, the problem isnt new players, its deliberate parasites. Someone can make a gunship plant, comdrop without a single mex, and start comrushing the enemy start position. He can then pump gunships without taking a single mex.

But, given how terrible planes are at taking mexes, it was impossible to start air before this unless you started on a big heap of metal spots. But it wasnt that the tactic was bad- it was still possible if players shared deliberately and could be quite effective. The problem is more players who deliberately dont make metal extractors, expecting other people to do so. Perhaps a 25% or so income from your own mexes would help with this. In a situation where a player has 4 mexes and another has 12, player one would get 1+6(7), the other 3+6(9). If at 0 and 16, it would be 0+6 vs 4+6 (12). Just something to ponder, if we think communism is encouraging antisocial play.

Communism is a nice automatic aid to teamwork with some players being more offensive (airrush) and others starting a light factory and splurging* all the mexes with 5 con rush.

And it reduces arguments when semi-noobs don't take the mexes just outside their base for the first 4 minutes prompting better players to take them.

*Splurging: the act of doing something in all direction really really fast

The investment in mexes and cons is not insignificant though, in fact, sometimes i think the investment should be larger.

Either way, mexing someone elses expansion when they arent pushing forward their line is bound to get raided anyway.

Oh well, i think either system has its advantages, but communism is an improvement.

Actually the major com rush ive seen isn't planes, is running as far as you can and boosting porc after you get a fac and a couple solars. Of course there are issues even with that(ie, your opponent catching on and sending skirmisher squadrons)

But yea, as is, Communism is an improvement.