Finally confirmed! Thankfully
However, lessons have been learned HERE, and I thank those who have contributed. I buy and sell bitcoin. It's my job, literally, and often, I buy from and sell to people I don't know. I have basic knowledge of the blockchain, and I have never had any scares until now.
I am going choose sellers more carefully and will set rules for them. If they want to get paid immediately after they send, they will adhere to my rules, otherwise, they will be paid after 1 confirmation.
I'd make it two confirmations.
Blocks can be orphaned making your one confirmation become zero.
For that I'd say expect at least 2 confirmations or 3 if you can get it.