Culture warfare and the Vasari

Their culture bonus supplements their military focus, since their ships can do up to 15% more damage in areas under their cultural influence.

Put simply - yes.

For the following reasons:

1) If you don't have culture to push back enemy culture, your planets can be overthrown (same for all races)

2) If you don't have culture around your planets, the enemy can colonise them when they bomb them into the group (same for all races)

3) Each race gets a difference advantage in culture... Vassari get bonus damage (depending on the research they have performed).

So you basically do it either to protect your planets/deny them to the enemy and/or to get a damage bonus

For all the above reasons and the 10% bonus you get for your economy.

Good point - though this is technically true for all races due to the bonus loyalty (20% if advent with research iirc)

well with the starbases advent can get +50% i think

I think not.

Actually, yes, I've had my homeworld (as Advent) at 150% allegiance just for the hell of it, thanks to the 2x15% provided by the starbase.

In my experience, you won't win the game with culture (unless it's an MP game and your opponent sucks, or you are playing against easy AIs), but you will lose the game if you don't research culture.  You need it primarily to counter then opponents culture (thus protecting your border planets from revolt) and to slow down enemy colonization of your territory if you lose a planet while your main fleet is distracted.  Look at it as a defensive measure.  The 10% economic bonus is nice, but won't make/break your game most of the time.  Losing planets to hostile influence without a shot being fired will make you lose.

P.S.  The 10% loyalty bonus has a much bigger impact on large maps, when a lot of your planets are 5+ jumps away from your homeworld (or in a different star system).  It makes your oultying colonies go from 25% loyalty to 35% loyalty, thus effectively increasing their productivity by 40%.

That is either only on one planet and you have to upgrade every starbase, or it's a bug.  Eitherway, Entrenchment IS NOT OUT YET (just in Beta), and YOU SHOULD NOT suggest stragetgies that don't work for 99% of the population.

Ha, I remember when I first saw that I could do that.  I didn't think the allegiance % counter for my planet could get any greener....

In response to the OP, I love setting up one or two culture centers on border worlds and, when I start attacking, on captured worlds.  It's great to constantly be receiving the culture bonus, and also be denying the enemy his. 

I think when IC gets around to doing that diplomacy expansion, culture will be a viable method of winning(at least it should be for the Advent).

Valid point-it does take a starbase per well, as it redefines the well's maximum.  However, given that the upgrade costs were intended to be placeholders, and that civilian upgrades are likely to be cheaper than military upgrades, there are instances where it may be worthwhile.

with this i had a (that is one) planet with + 5,x crystal (or metal). Get the allegiance to 150% + Resource Focus

Culture is more defensive than offensive.  You won't kill your enemy with it (most of the time, anyways), but you could suffer if you don't have any of it yourself.  Most of the time you only need one broadcast center for every four or five planets, so it's not exactly an expensive proposition.  As well, culture will raise the loyalty of nearby planets, which can help your income somewhat.

That said, there are a couple of cases where offensive culture is helpful.  If you can't spare an attack fleet to finish off an enemy in a free for all situation, culture can be a good alternative to keep them down.  It'll force them to replace trade ports with culture centers just to survive, killing what's left of their economy.  As well, although I doubt it would work in multiplayer simply because of the time involved, if you can get half a dozen deliverance engines as the Advent you can cause a revolt on any planet you want.  I found last night when I was finishing up a nine hour massive multi-star game that my deliverance engines were clearing enemy planets at a considerably faster rate than my fleet.