Do not open the door, its an electric and it does take additional time to rebuild the smoker temperature. It won't need any mositure or shouldn't, I have done a butt really low and slow with the smoker at 220 degrees for 22 hours, I pulled it at 204 IT and when it came out it was like shreding butter. You don't need to do it this low and slow for a great pulled pork. I was just playing like it was the olden days.
You do not have to run a continous smoke. Even Jeff has said that at temperature the meat loses its ability to take on more smoke. 100 to 140 degrees being the optium for smoke. A continious smoke is what fire burners do because they are continously opening the pit and moping or spritzing or saucing trying to help the moisture. They have to replace that smoke constantly.
You have a locked down gasketed door and for the most part the only way the smoke and moisture can escape is the top vent assembly. Leave it about 1/2 open to start then regulate the vent to maintain a slow near clear smoke. This means your smoker is running at max. efficency. White smoke a Guru here will say, has no taste. LOL
30 to 45 mins to a load, do not over load, after about 3 loads you must remove the tray and dump it. More smoke is not always a good thing. Yes in the long run you'll want to try an aux. smoke generator, but for my 2 cents I would look into a remote sensing thermometer first. That way you can insure two things while learning, that you will not make anyone sick, and that everything you mess up will still be delicious to dispose of..... OOne of the nicest things about a electric smoker with that remote temp sensor and an
AMNPs is you can sleep all night.
Remember, keep the door shut. I have heard its a 15 min loss everytime you open the door, 4 times add an hour to cooking.
PS no foiling will increase the cook time, foiling is supposed to help with the stalls you will see when you get a thermometer. But if you've got the time, no foil is really needed, its just another handy helpper. You should also see a better bark this way too. But if you want that butt for supper, I'd foil to make sure.
Good luck and don't worry, enjoy the smoke.