We use pre-ground beef all the time. We have had years where our deer harvest has been low where we have had to add ground beef to our usual venison/pork mix. We have use both 80% and 93% depending on beef prices.
We usually make our sticks in the Fall when we have cooler evenings, so we just hang our sticks on racks in the garage.
Regarding the use of pork, yes I do think that the pork adds to the flavor profile especially when using lean venison or ground beef. We usually use about 1/3 pork.
The Excalibur seasonings from Walton's are the best that I have tried. I've been using them for close to 15 years now.
Good luck with your sticks and make sure to take/share some pics.