‘[video] games employ and deploy racial, gendered, and national meaning, often reinforcing dominant ideas and the status quo.’

As do every form of entertainment media in existence. This is like observing that English-speaking peoples write books in English. Duh. Perhaps this statement is simply meant to set video games on an equal social footing with more traditional media? It's not a particularly profound sentiment.

‘virtual conquering [is] the basis of video game popularity and power’

As others have said, this is the natural format of competitive or progressive play (including sports). However, there are other forms of gaming, such as community or sandbox style games.

‘[video game player’s] trigger happiness becomes a metonym for [a reflection of] their happiness with American military efforts’

That's a determination made on a case by case basis. Certainly someone with a high interest in the American military is going to be attracted to a game ABOUT the American military. Whether or not you consider the American military "trigger-happy" is entirely subjective, and difficult to reflect in war gaming. Serious war gaming is as much about fire control and discipline as it is about shooting. And how squad-level tactics (either free-for-all or disciplined) translates into global policy is difficult to see.

‘the bloodlessness [within video games] contributes to an increasing acceptance of war’

This is an old argument, and has some merit - the removal of consequences in entertainment can alter your perception of certain activities. One of the more famous examples of this was the normalization of alcoholism in (don't laugh) Cheers. A bunch of characters sit around at a bar drinking for 10 years and no one ever got drunk. This has a subtle psychological effect of disconnecting the activity from the consequence, at least subconsciously. So you could argue that constant immersion in an environment that makes killing and combat fun and profitable could influence one's attitude toward war. It is, after all, one of the army's recruitment tools.
All of that does not switch off free will and the lessons of personal experience, however. If you have a relaxed position on conflict, pain, and human suffering it has more to do with your own prejudices and fears than anything you learned in a video game or movie, IMO.

‘Although war may seem harmless on the computer screen, this very harmlessness ironically elicits consent for U.S. foreign policy.’

Derivative politically-motivated BS. See above.

‘We are teaching children to associate pleasure with human death and suffering. We are rewarding them for killing people. And we are teaching them to like it.’

Again. They said this about TV, about movies, about rock and roll. Media does have a psychological and behavioral component to it, otherwise we wouldn't spend billions on advertising every year. But this grossly overstates the effect, and is indicative of a larger witch hunt.

‘[video] games teach … citizens to support murder without remorse.’

So does Jack Bauer.