Need Help With My Players

[5crownik007]

Hello.
I'm GMing a group of four (or maybe five) people and I've been having objections to their behavior for some time now. It causes all of us to have a worse experience while palying and I've been wondering what to do about it. As such, I've taken the responsibility for their actions onto my inaction, rather than blaming them directly.

We've been playing in the Stars Without Number system, but we've recently wrapped up our campaign and have decided to move systems and setting to GURPS. We have not begun any GURPS sessions.

Here are our issues, but let's first anonymize our four players, Max, David, Millian, James.

Max is almost a participant only in name. He arrives to the game, gives advice to other players and his character avoids interaction with any NPCs or doing very much of anything. He barely participates in the game. I am certain that I have provided opportunities for his character to act, but he has not taken them.

David gets unreasonably angry whenever the party fails to accomplish something or loses to the enemy. He calls his class completely useless. He's a psychic who dishes out most of the healing, I can think of several TPKs that would have occurred without his presence.

Millian is one of my friends in real life, and it seems he has trouble sleeping. He's an insomniac, so his solution to his inability to sleep at night was to sleep in the middle of the day, missing out on any and all events that happen in the day. His character, while incredibly powerful and occasionally acting like a meme, was an excellent catalyst for bringing about actual roleplay, and people eventually complained that he was receiving too much attention, to which I later protested that "He was actually doing things, you were just loitering."

James seems to be the best person in the party, with only minor issues. He frequently adds a lighthearted "memery" touch to serious situations, like sneaking a bomb into a military encampment, or using his ridiculously overleveled persuasion skill and high charisma to trick guards into watching entire movies with him(his character was a robot AI with a television for a head). Although, he frequently participated in "rules lawyering" and questioned my decisions endlessly, he did in fact help to provide a better experience for other players with this quality, on occasion.

How do I get my players to co-operate with me? Please send help, they're breaking down the door right now.