There are some useful tools in Stellaris that aren’t exactly well advertised, that people might not know even when they’ve put in the hours!
Here’s one: you can restrict a system so that your ships automatically path around it and not, say, directly into the leviathan. It’s a button on the bottom of the screen in the system view.
Oh good call out!
The outliner options in general are so good. It’s the little cogwheel on the top right, lets you rearrange things. The tiny outliner mod only really lets you use planet designation or type, but the vanilla one also has designation over type and type over designation:
Edit: And for anyone else seeing this, the little cycling arrows beside it lets you sort your planets!