Max everything except raytraced shadows. Play with advanced settings and see what you think looks good, but in general the lower on the dropdown menu, the more costly the setting is in terms of fps. You can probably max them anyway.
Never drop back to a lower version of DirectX, why would you?
True, but a game nailed to 60 fps unwaveringly does feel pretty slick. I’d find it hard to say that more fps would really help.