If you're going to cold smoke sausage, you have to use a cure to prevent botulism....
If you're going to use Cure #1 (not Morton's Tender Quick... the two are different things) then 1 LEVEL teaspoon is required per 5# of sausage. I don't use Tender Quick so I can't comment on how much to use but the instructions are on the back of the bag. Cure is one thing where more is definitely NOT better. Use it exactly as the manufacturer specifies.
As for cold smoking sausage, (I call it cold smoking but it's really not smoking at under 100* as cold smoking really implies) here's what I usually do for smoked kielbasa and andouille
After you've stuffed your sausage, hang and dry the sausage over night in the fridge. This lets the casings dry out and also lets the seasonings in the sausage meld....
Next day smoke the sausage. I roll smoke the entire time:
Start out at 130* for the first 2 hours. This helps dry the casings further.
Then ramp to 165* for ~ 2.5 hours
Don't go strictly by time, you want to smoke to a finished IT.
I smoke to an IT of 152*. I also cook this sausage when I'm ready to eat it. I do not eat it prior to cooking after the smoke.
Hope this helps. Shout out if you have any more questions.