Heating penne pasta and Italian sausage sparately
My grandson's Christening is Sunday and we have to leave the house at 11:30 and wont be back until about 3. I will be making Italian sausage for 40 and baked penne pasta. I would like to know if I can put the penne in my 18 qt. Nesco buffet pans cold, turn it on to 250 when we leave. In my other Nesco, I thought maybe place the browned Italian sausage in the marinera sauce and put on 250 also. Would this work? We would like to serve around 3:30 and of course my oven just broke, so both have to be done in the roaster pan. Also, I just bought the buffet inserts and have never used them, do I put water in the main roaster to use? They didn't come with instructions! Thank you in advance
DO NOT use the buffet pans to reheat, it is not safe.

Yes, you do put water under the buffet pans, in the cooking pan, not in the roaster well itself.

Yes, you can reheat as you suggest. I would not cook the penne from just mixed this way, I would bake it done ahead (180 degrees temp in the middle), chill, and reheat. It might not be done if cooked from just mixed, and it might not get all the way to 180, which is a food safety issue.