New BWS Fatboy for me

Congrats on your new addition. Unfortunately I can't answer any of your questions, but get that thing dirty:thumb:

Congrats on your new cooker.
You're going to love it :clap2:
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*No need to line water pan with foil.
It is a good idea to spray water pan with Pam prior to filling up for easy clean-up.
* Hot water is not necessary by time fire settles down water will be up to temp.
*Water cookers tend to cook faster than a dry cooker but with that said your mileage may vary.
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I would invest in one of these for quick start ups.
Harbor Freight Propane torch

Congratulations on the new Fatboy!
I don't line my water pan and have no problem with cleanup. I use a plastic scraper to push everything into the drain while the cooker is still warm. Don't leave the water pan full between cooks...it promotes rust.
I try to use hot water whenever possible to speed up warmup time and conserve fuel. If you don't have hot water it's not a big deal. You will need to adjust your startup timing and will use a bit more fuel.
I can't comment on the difference in cooking times with a BGE. I transitioned from a WSM and found the cooking times to be noticeably shorter on the BWS.