You must get a police report first.
Also, you might get lucky and find someone has handed it in. When I went years ago after I lost mine, there were about three boxes of lost passports.
Good luck.
I have seen a few locals trying to stop their bikes by pressing both feet on the ground, as they have no brakes. Always makes you wonder if and when they will come a cropper.
Opened a Bangkok Bank account by myself a couple of months ago. No talk of insurance. They only wanted a Certificate of Residence. Bank staff were extremely helpful.