What I've been doing for years, is when I have food above my AMNPS that isn't in a Pan, I put a half of a foil pan upside down above it to keep drippings off of the AMNPS. You can see all the drip splatters on the Half pan in the picture:
Incidentally... I have found that that oval drip pan doesn't cover the AMNPS from drips very well. I have taken mine out and I use one of those rectangular (foil lined) disposable aluminum pans, and that fits in there pretty good in the same spot it and protects the Amazn better.
Depends on your taste.
Is there a need to have smoke more than 2 1/2 hours of cooking?
I like the cold smoker attachment also, No problems and you don't have to worry about lighting it or blowing out, the only thing is it doesn't smoke as long as the a-maze-n does and you have to run electric to it, I do have the a-maze-n also.
If you buy the cold smoker attachment, it gives you tons of smoke. I always use it whether I am cold or hot smoking. I swear buy it. It's relatively cheap, $50 at Walmart.
Is there a need to have smoke more than 2 1/2 hours of cooking?