Bigboy, as long as you had them at the temps you did you shouldn't have to worry about putting raw pork with raw beef; hell, plenty of folks add minced bacon to their ground beef as the form the patties. Based on the visual evidence, this looks like a rousing success.
Glok, with an 80/20 mix, plus the fat from the sausage and the addition of the parm cheese it shouldn't dry out. These components would also help if you take it to the grill after the smoke; I like an aggressive sear on my burgers so a quick trip to a high heat cast iron skillet would give it a neat textural component.
One last suggestion; taking the freshly smoked burgers and vac sealing them will also give you some VERY quick meals that are a good alternative when you don't have time to fire up the smoker. Throw them in a skillet with a little reserved bacon grease and you'll bring them to temp and get a sear in one fell swoop.
