No, no, I get what you're saying. I tend to think he's more benign in non-magical medicine. As for the other stuff, I have a feeling Gaius almost justifies it to himself as saying, "I'm only acting sketchily because Uther acted sketchily. He started it, and I'm just picking up the pieces." Maybe Gaius has control issues. Like, if he lets Morgana know, who knows WHAT she'll do, he thinks. Endangering herself and possibly implicating himself. Also it's Uther who asked Gaius to drug Arthur, and how do you say no to your king? Especially a violently punitive one, who has been known to chain up his own foster daughter in the dungeons. Gaius maybe recognizes that he's only passing the buck here, but maybe this way everyone will stay alive. Maybe it's a habit he picked up from the days of the purge, doing what you need to do and shirking responsibility. No one ever did anything, during the purges, and yet things got done and people got arrested anyway. I WONDER IF Gaius, at the root of it, is ultimately just protecting everyone from Uther, even Uther -- another habit developed during the purges. As much as Gaius has come to care for the old king, he still sees what a nutjob the guy can be.

In non-magical medicine, I do imagine he takes some liberties. Like maybe someone was going to lose an arm, but then she has children to take care of, so Gaius magics it better. But he tries not to be extremely successful, because that might attract suspicion? He goes for 'very competent'.