I don't use mine to connect to mixer inputs ... except for a stereo pair that I use to connect keyboards through ... all the mix inputs go straight into the board from the other room. I haven't had a need to get those to a patchbay first, yet.
The other I/O devices I connected to it are CDRW, analog PC, Tape and a couple of Effects processors that I don't have directly connected to the mixer. ... I also have a send to a listening room that I use during mixdown. That was the band can go in the other room and party, while I mix w/o distraction.
There's no rules when you set up your own bay ... connect the things that make sense. A good way is to notice what you keep plugging in and pulling out during a session. If those connections were at the patchbay, you'll save time and headaches by connecting them there. I'll eventually terminate the mic inputs at the patchbay too ... but I'll wait until I get a dedicated bay for that.
Hope that helps.