Well concerning Guzma we do know he had home problems. No matter how well he did he never was able to meet the standards of his father (which must be pretty high because, sure, Guzma mostly had bronze and silver trophies but that means he was usually in the top 3, how many trainers went home with nothing/participation medals? Seems if it wasn't gold it wasn't good enough for Guzma's father). And seemed like his father had anger problems because he would then beat Guzma for not doing "good enough", implied sometimes with a golf club. That kind of abuse at a young age can really mess with a person's head, it wouldn't be a surprise to me that Guzma relates physical violence to a form of affection as that was his relationship with his father who he tried his best to impress. He beats up his grunts because in his twisted way he cares about them and wants them to do better. Originally he wants to beat the player because they're in his way and defeated several of his grunts, but later on he takes a liking to the main protagonists and wants to beat them maybe out of obsession or looking for some gratification (either self or maybe even from the player). About the only person that Guzma "beats up" and that he doesn't like is himself judging on the way he berates himself about losing.
It's been well known that Rocket Grunts, well, grunts in general aren't the sharpest knifes in the shelf. He was told "stand guard and don't tell anyone to look behind the poster and activate the switch" and that's what he did: he stood in front of the poster and told anyone who came up not to look behind the poster or activate the switch.
He would probably receive a poor evaluation for taking his orders too literally.
Clyde's initial lines may be GF trying to say "look, we can't let you play the slots, just continue playing the story".