This only relates to the macOS crashing problem. I know nothing about macOS or MetaMask. I posted links to other topics with solutions per the macOS crashing issue in a related topic. These solutions involve “deleting the Brave-Browser-arm64 folder (in /Library/Application support/)”. You might want to give it a try if you haven’t already. The link to the post is below and it has a little more information about the solution.
As for the MetaMask issue, I suggest you open a new support request specifically for that issue, especially if the above works for the crashing issue. It is easier for community members and support staff to have information relating to only one issue. Also, there are several topic about MetaMask issues in the community. You might try Search to find other topics related to your issue.
I did a search but it was all too confusing to me! I picked some of the topics that looked like they might apply and posted below.
This extension may have been corrupted.
Brave has wiped my metamask wallet saying it was corrupted and now I can noBrave has wiped my metamask wallet saying it was corrupted and now I can not access the certain adress that has all my tokens!