You can get some smoky flavor when you cook the fresh sausages by cooking them over coals, with wood chips, etc or if you happen to have a pellet burner of any kind. I cook my fresh sausages on the pellet grill, however this is NOT the same as "smoking" which would be low and slow for several hours. I roast mine on the pellet grill at about 300 degrees until meat thermometer reads in the safety range for the meat involved. This generally does not take long- 20-45 minutes max, but does add some smokey flavor to a non-cured sausage. Otherwise, it is just not safe, as some of the others have already explained.
As far as cure- the type of cure you use is generally specific to the recipe. Some use cure#1, also known as Prague. Others use Morton's tender-quick which is a completely different product, and it can NOT be interchanged with the Prague cure part for part.
When working with smoked and cured sausages, it is best to follow a safe, tested recipe for your first time to ensure success and safety.
There are many recipes on this forum and on the web that are instructional and safe. You can pick one and run it by the knowledgeable folks on this board to get suggestions.
Your fresh sausages look great, once you eat your own homemade sausage, you will never want another store-bought...ever. I just finished up a bunch of lamb with feta and pork/garlic/red wine which are both fantastic.