the lab leak was a viable theory initially, now personally i am not clued in enough to say whether it is or isnt still on the table.......... but at least at the start it was a possibility due to where it was based and what they were working on. To suggest it is a possible source isnt being a crackpot. To categorically state with certainty that that is where it came from and its all a monumental cover up.......... that is different imo.
vaccine side effects............. i dont think anyone would say the vaccine has no side effects, however the crackpot theory is to suggest it was all a monumental coverup to make money and that the vaccine risks on the whole are even remotely close to the risks at the time of getting covid without being vaccinated.
mask efficacy - imo the problem is many people do not use the masks properly and do not fit them properly. The correct mask fitted well and used correctly will help but not a magic bullet. 2 people wearing well fitted correct masks even better..
however some disposible mask reused for weeks on end, worn so covers mouth but not your nose isnt going to do much.
also it seems the mask protects the population from the wearer more than the wearer from the population. So for instance i have not normally worn a mask for ages now.......... but IF i had covid but for some reason i had to go out and could not get around it, i would wear a mask...... not to protect me, but to try to protect you............ you are welcome btw!.