Once you get your new passport you will need to take it to immigration to transfer your visa into it. You keep the old passport the form just needs the number so take the old and new passport to immigration
it is per person. I highly recommend doing this rather than trailing spouse simply because if the main spouse has to leave or god forbid something happens - trailing spouses only have a short period to leave.
Once the bankruptcy has been discharged it's no longer relevant. If you are still in process of the bankruptcy, you likely cannot leave the country until it has been discharged. I am assuming you have it discharged though and are financially stable now.
We weren't even asked a question about it during our application, so it never came up. Had it I would have had to say something as I filed it years ago after a divorce that left me financially struggling after he emptied my accounts. (yeah, sometimes it is the woman who gets screwed over, believe it or not) they never asked and it never came up through the process.
You will need to fulfill the financial requirements to gain the correct visa. For example ours is a non O retirement - 800,000 Baht retained in a thai bank and I think there are times you can use a portion (but better to just leave it there for insurance / emergency use purposes) and then you need enough to live on besides those funds.
You can get the oil from a cannabis pharmacy and the gummies almost any pot shop (Bangkok was the only area I found that doesn't seem to have them) I get mine in Hua Hin, so it really depends on where you are. They have different potencies and take about an hour to kick in - usually dose off before that happens but I sleep pretty good using them and they have been a big help for pain management for me as well.