Diplomacy is kind of weak......

I agree that Diplomacy should be improved. But I can't agree on the borders part of what you were saying. If you don't want people in your territory, then by all means lock them down. I know that in my last game, just for fun, I positioned ships along my entire border, just to keep out what I didn't want. If you don't put in the effort to stop people from wandering through your space (which, as they say, is big), then there shouldn't be any problem. If you want a RL example, look at the US locking down on the Mexican border. They obviously don't want people crossing, so they post guards on the border. If you don't want border crossing, do the same.

Anyway, on the rest of your stuff I more or less agree. It's too easy to get a diplomacy victory, and to become allies with races that shouldn't like you. Especially the Korath. I allied with them out of self defense, but they were at close when the galaxy turned on me. Same with the Korx. It doesn't make sense to me.

Mexico isn't rolling tanks across the border.  If I see another civs warships roaming through my territory there should be some diplomatic option to demand that they leave my space, or better yet, have some diplomatic agreement with that civ for them to respect my territorial sovereignty to begin with.

I agree, space is big.  So if they want to try to enter my territory without me knowing it they should be free to make the attempt.  But if I ever detect their ships in my territory on my sensors it would definetly sour diplomatic relations.  The same goes for me entering their territory when they don't want me to.

The ability to have closed borders as a diplomatic option is a long overdue feature.

OPTION: Blow them up!!!   Yea, sure it'll start a war.  BUT you'll get your point across...  

In this game we don't "own" space. The shaded region is our area of influence only. The concept of rights-of-passage was discussed a while ago and the devs gave the reason i just stated for leaving it out. This game is different than Civ IV in that we can't just colonize anywhere we want; there has tyo be a planet to get to AND not all planets are the same quality. So if we could keep out other races, all we'd have to do is colonize a planet a bit far away from our home world and then everything inside the shaded region will be ours alone, to colonize when we got around to it. You could control the whole colony rush.  That is once the areas of influence met. Then everyone would be complaining about how easy it is to win an influence victory or how its canm be exploited.

Unless things have chjanged with TA, i never found alliance victories to be easy. There are many factors that play into your relations with the AI, you can see them in the foreign relations screen. Enough plusses and you get close relations. I do susspect that not all of the plusses are weighed the same by the AI though. I only have DA but at higher difficulties i sometimes can never get close relations. The reason you were able could be based on your military rating. This game weighs your military porbably more than anything when determining relations. Trade routes are a minoir plus. On the flip sidfe, I've had trade rouites with races that have declared war on me for having a weaker military. I think ethical alignments play a large role as well. Usually the only time i can get close relations is with races that i could steam roll over anyway. .

SMAC diplomacy was best there was... That i know ofc.

My military by the most part is strong, but that should make other races cautious, not close. The diplomacy just needs to be revamped. There is no logical reason why a race that i refuse to talk or trade with should be close with me. I have even paid for another race to go to war with my "close" friend and it did not change his view of me. I agree that military might should have "some" factor in relations, but that should not be the only factor. I still think that some sort of open border policy should be examined. I understand your objections, but it would bring a whole new level of diplomacy to play around with. My problem with the relations between races is that it is not based on any logical factors. In Civ-4, relations are based on proximity, trade, and strength of culture and technology. In GalCiv2, i just don't see the same parameters that govern relations. If i don't trade or agree to assist you that SHOULD effect relations, but in Galciv 2, i just don't see any effect for turning other races down and refusing to talk. To me that is a broken system.

Mexican tanks are a bad analogy. If anything the ocean is a better analog for space than national borders. Foreign warships routinely pass through stretches of ocean claimed by various countries.

The diplomacy win in Twilight is probably easier, but that's a game strength. One thing that's done better than in Civ4 are computer players reacting to past behavior. If you get a couple of the minus modifiers for going to war or conquering others you can lock yourself out of it. The reason Terrans have an easy trip to diplomatic victory isn't just the super diplomat ability, it's that having the ability forces you to play nice and take actions the AI smiles on.

I'll grant you that it's likely faster, on average, to secure a diplomacy victory with the Terrans than a conquest victory with the Korath. But it's worth bearing in mind what happens when the positions are reversed too. Should your continuous sporing slow down, you can solve that by judicious use of Operation Big Hammer. You build up an even larger military until they beg for mercy. The Terrans, on the other hand, have to research and then build a military if diplomacy fails. So while one is faster when it works, the other is faster when it doesn't.

The worst part to diplomacy wins in my book is the fact that they're entirely too easy to finalise in a week. Once I've opted to take that road I'll wait until I have close relations with everyone else, negotiate peace accords between all warring civs (perhaps throwing in the alliance tech to sweeten the deal), form alliances with everyone, then hit return. The problem isn't so much that it's easy reaching close with everyone, as much as the fact that you can completely eliminate the risks of forming alliances.

In many ways, it is the only factor. I think (pretty sure, but it was a year or so ago) that brad said diplomacy was intended to be viewed as the option that holds off the inevitable war. This seems to be the case, as you can pretty much ensure yourself an alliance victory simply by being the biggest bully. Which I guess, is just a shortcut option for the player if they wish to discard the late game sweep up.

I would love to see diplomacy vamped up to, but unless some pay-for modules come to pass, I think that may be GC3. Then again, maybe "not-MOM" will have a more complex diplomacy system, that allows the weak to unite against the strong. Or the strong to make use of their mates as some sort of goblin toss/club. Fingers crossed.