I wait until my temps have stabilized at the temp I want to cook at (250-275), then I put the butts on. Usually takes about 20 minutes or so, and the white smoke is usually gone by then.
I leave all my Weber cookers (Genesis propane, 2 WSM's, and a kettle) covered and on my patio all the time. For the winter I place a
large plastic garbage bag over the WSM's, and then the cover on top of that. It prevents any rain or snow from
getting to them. For over 20 years never had any...
Gregory, having been a WSM owner for over 20 years (initially an 18 and then later the 22" I own both now) the accessories you mention you would include are"wants" and not "needs." I always recommend to folks that if they buy a WSM, that they learn how it works before purchasing any mods for it...
https://www.amazon.com/dp/B0CK2QLN7S?tag=tvwb-20 I bought this from Amazon and it does a great job scraping off "gunk" from the Weber Kettle and the WSM. The curvature of the scraper matches the curvature of the grills perfectly.