but my question is should my wife apply to the same cards so we can double the earnings? Also, what is the consensus on keeping or canceling cards once the membership fees are due? I believe a few of the cards the first year was not waived but I don't mind when taking the end result into consideration.
you could get your wife to apply... but does she qualify (FICO score on her end etc)?
For some cards, you can downgrade to no AF versions, but you might lose out on some benefits. Keep it if the benefits are worth it to you (eg checked bags, hotel rooms, lounge access). Cancel it if the signup bonus is churnable
eg: CSP-> Chase Sapphire, you keep the UR points, but lose ability to transfer to a travel partner