Seperate it more from the other options, because at the moment it's not hard to accidentally click on it when you mean to click on options instead. A whole Button width gap between Options and Save and Quit should aleviate this.
Confirmation Dialogue boxes are annoying. When I click a button I usually mean it to do what it says. For example, quit, then a confirmation dialogue box comes up asking "are you sure you want to quit?" Why would I have clicked the button if I wasn't sure? In this case it's because the buttons are too close together, but there is loads of space available that they don't need to be so close. Long Story Short: I hate confirmation dialogue boxes
Constructive criticism only please. I've only accidentally clicked on the save and exit button once, but even that is once too many, and it's such an easy thing to space the buttons a little further apart I don't understand why I'm being treated as if it's an unreasonable suggestion.
Fun fact: this reasoning can be used to refute your original claim, regardless of how close the buttons are. On a standard monitor at any resolution there is plenty of space between the buttons for any normal player. Unless the mouse or hand controlling it moves erratically these accidents shouldn't happen. Also, if this gets ported to consoles save and quit will need an extra confirm screen, as all three consoles require a confirmation message preceding "destructive" actions in most cases. Unrelated but just a note if it ever comes to consoles. All my nitpicking about your reasoning aside I wouldn't hate this change. It doesn't hurt anything after all.
How about we get confirmation box for the options instead? But really, if you misclicked from options to save & quite, it *could* happen even with little extra space between them. They're not gonna move it half the screen down.