I'm not so negative about the whole thing the way Kraco is. I think that doing "piracy" more as theater and less as actual hijacking is a good thing, for all involved. The helmsman said it himself, guardian ships so rarely get to fire at anything these days. Everyone operates in a large galactic empire that is, curiously enough, peaceful. The customer gets a little excitement without the risk of their ship actually being compromised and everyone aboard breathing vacuum (which as Ririka showed, is alarmingly easy to do with handheld weaponry).

Nor do the pirates have to worry about much of a risk (in part due to the Bentenmaru's superiority) when attacking or boarding. The wealthy aristocrats think of it as a game and something to brag about to their equally frivolous and bored friends. They're not about to fight back, the cruise liners are insuring all their belongings. Perhaps it is more that the pirates are choosing their contracts very carefully. If they went after non-luxury liners, they might have to risk fighting with passengers or crew. People with something to lose.

It's win-win. As Ririka also mentioned, it's best when you only need to use the threat of violence. Pirate Theater accomplishes that nicely.

Marika's attitude is a problem. Chiaki and Mami recognized it, as did Misa and Kane. She's convinced she can do school and her two jobs, but it's becoming clear that Marika can't handle all three, or even pirating and school. There's something behind why she so badly wants to complete school, but trying to handle all three seems to have something to do with surpassing Ririka, as Mami also mentioned. I think that the next big hurdle for Marika is that she is going to be forced to give something up. Piracy isn't as simple as Marika wants it to be (neither is maintaining the faith of one's crew in their captain), and school requires equal effort.