Has it been 24 months since you received the SW bonus? If so, I would cancel now but hold off on applying until a better SUB comes along, hopefully soon.
I would keep your Chase Slate, no point in closing a card that doesn’t have an AF that you’ve have for 5 years. And yes, keep the BOA card open.
Another good all-around card is the Freedom cards. it doesn’t appear you are interested in Biz cards?
Other than a VERY occasional sale on Poshmark, I don't have an activity to support a business card. And yes, my SW bonuses were well over 24 months ago. Those cards were issued in 2011 and 2015.

And yes you can call or SM to have the card expedited