There is no good reason why the M key and the escape key should close the inventory and the character sheet. I'm sick of having to close and reopen them every time I want to save the game; and I need to save the game a lot because the game is so unstable, especially when I'm playing using mods. The "M" key at the very least should be changed to exclusively open the menu and do nothing else. (Possibly the Escape key too, but that's not as important, as Escape is at least a key that you might expect to close things)
I don't save every 5 minutes. I only save either when I'm about to descend stairs to an ungenerated floor or if I need to take a break. Pretty much ALL of my Game Crashes happen when I'm using stairs, especially when the game autosaves at that time. If you're still crashing mid-floor, then maybe you either have too many mods installed or you might have an unstable mod installed.
I like playing with a lot of mods and this simple change would make it easier. Plus, there isn't any good reason why the "M" key should close dialog boxes either way.