How much negative offset before a lack of mud flaps becomes an issue?

Recently put on some SCS Ray 10s which have a -12 offset. So now the tires are out just far enough that I am wondering what the sides of the truck are going to look like next time I drive around on wet muddy roads.
I know a lot of people like to add mud flaps even without negative offset, even just to protect other vehicles. I don't really care for the look however and would prefer not to add any unless there is a large chance I am going to start getting rock chips. I don't care for the look of rock chips more than I don't care for the look of mud flaps!
Will a -12 offset cause issues along these lines or do I not have anything to worry about?

 

Even with like a 0 offset your front wheels will spray back and your rear panels in front of the rear wheels will eventually get shredded.
Same with motorists driving behind you. I live at the end of a long gravel road and my rear quarters are fubar even with mud flaps.

 

You are causing me to question my purchase. How dare you sir! Just kidding. So I guess the effectiveness of mud flaps depend on how far they stick out anyway. So if the tires are sticking out the mud flaps need to as well. Sounds like I need to do more reading about them.