Tau are more humanitarian or utilitarian than outright communistic. Not everyone has the exact same set of skills, but certain sets of skills are required to perform specific roles better than others. In an MMO, you wouldn't send the tank to dps, or the dps to tank, would you? This is what gave rise to the Caste system of the Tau. They let certain groups of people focus on an aspect that their society requires to the exclusion of all else, so as they may master that one thing. Having 25% of the population doing one thing 100% sounds the same as 100% of the population doing 25% of all things, but the point is that one person can really only do one thing at a time.
The idea that each Tau person, and each member of their allied races is equal is less true in that particular wording. It is that they, and the roles they perform, are all equally important to the growth and advancement of the Tau Empire as a whole.
I also don't think their aesthetic design relates to any anime/Japanese style that I know of. I like to think I'm rather seasoned in Eastern style mecha, and conclude that XV8 Crisis suits look nothing like anything I can reference. The Tau Fleet is an exception to this because they look like rather generic ships, and can't really draw any reference because space ships don't really exist IRL yet. Their aircraft and transports, gunships, etc are usually much wider than anything I can reference.
Enough about Tau, more about the Bolter. Part of its operating principles and mechanisms is that most of the propulsion is contained within the warhead itself, as it is rocket/gyro-jet powered. Recoil is minimal, which lends itself to rate of fire. I haven't experienced the route they're going with this, but I honestly don't hope they make it a bullet hose. Glorified SMG's always make me cry because they are designed only to trickle that little spot in the back of your head that hasn't quite grown up yet. Granted, the entirety of 40k is designed to that effect, it at least offers a bit of seriousness now and again.
Now, onto the actual topic at hand. I'm quite excited for this game. The concept behind 40k space marines is fresh from even the Halo space marines, which seems more militaristic and serious. 40k is just over-powering and bursting with color and gory glory. Instead of relying on special tactics (GoW) or special gear/gimmicks (Halo), you just run fearlessly straight into the heart of the enemy.
I think a valid comparison would be those hack and slash dungeon crawlers, or just brawler games of that nature, not dry, gritty, 3rd person shooters (or shooters in general).