I think it’s unreasonable to think there was a motivation to intentionally release Covid.
I don’t think there’s reasonable motivation given when and where the outbreak started, how the virus works, China’s response, etc.
I think the particular scenarios you’re painting are also quite extreme/unlikely, so any claim that a virus was released intentionally would require extraordinary evidence in most cases/I’d rarely entertain that hypothesis. There are less drastic and risky ways with less blowback of dealing with all of those issues, even if you assume a very capable bad actor and ignore the normal and expected amount of incompetence and error.