O__O *mind blown* or well perhaps not really blown. <.< i did survive Asimovs books like the Empire -w- good lord that was some heavy reading. 
well i guess this will be interesting. Though im not sure if i want to join just yet. It's in Advanced roleplays and have stayed away from this section due to lack of confidence in my Rping skills :/
A few points from me to though. And this might become a bit lengthy :/

This part is about mech's and munitions
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Mecha. is usually 3 different types in sci fi for simplicity and somewhat realism. 
[b]Support class[/b] - it's about the size of a small car. About 3-4 meters tall. (the japs are currently building these for industrial work and they look like the ones from Alien :D )
[b] Fighter class [/b] - like a standard type and the biggest favorite in most lores - about the size of a fighter jet standing up. (I will refer to anime here and i do recommend looking at Gundam first but then mixing in Macross as they have the most details surrounding the architecture in the mechs)
[b]Behemot class[/b] - names can be varied on the class but it's my favorite these can be quite big. Up to the size of a cargo plane. These often go borderline close to walkers rather then mechs as they at times require more than two legs. 

If refering to a suit smaller than the Support class one usually go over to refering to them as Exosuits. Bio support armour and and so on. 

When it comes down to munitions with firepower. It becomes really complicated. A weapon can be quit primitve lets say about 150 years from today we most likely on earth will have munitions that fits into an assault rifle or perhaps slightly bigger and will have the explosive effect of todays 40mm grenade launcher munitions and possibly even more. 
There are already timed 7.56 mm rounds that can explode as shrapnel rounds and a guided version is already being researched in South korea and in the US even germany has started looking into it for special forces. [/hider]

Space and stuff that happens there
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Space combat and ships.
For the fleet bound nations. It would be more logical that they excel at space combat and maneuvering as a force. While lacking heavily in ground combat and more infantry based fighting. Zero G combat being an exception. Another weakness would be logistics and resources holding a higher value ot them and they lose more on prolonged combat compared to others. 

And when it comes to space ships of different sizes. and automation. Let it be more like this just as an suggestion. An heavily automated ship is more vurlnerable to cyber warfare and electronical attacks. While and more manual and manned ship is much less vurnerable to this. It instead takes longer to react, repair and move during combat since more manual actions need to be taken for things to happen.

As for the planetary part. Why is the Cold planet the one with the highest population and the green temperate planet the one in second shouldn't they switch in population?
Sounds more logical to me if a cold planet has people with good survival gear and somewhat okay population while the whealty planet has lots of people but not so good survival gear which = good durable military gear O.o [/hider]

And im going to hold my self back there and breath >,< sorry if this seemed like a rant nya!!