start the Non-O process in your home country. Come to Thailand and open a bank account. Transfer 800,000baht into that account from your bank in your home country. Then apply for the 1 year extension of your Non-O based on retirement. It's easy enough to do on your own.
what's funny, but not really, is your claim of "hundreds" killed in Colombia since Covid, when there were hundreds killed in one US city just in 2024. Colombia isn't 100% safe, but it probably isn't any more dangerous than America.
if you don't have a Non-O visa from your home country when you get here, you'll find it next to impossible to open a bank account without a visa agent. This is a bank issue, not an immigration issue.