as mentioned your visa effective date starts the date the visa is issued by the embassy not the day you arrive on Thailand. You entry stamp starts the date your arrive. What you need to show for the application process depends on the embassy you apply at. Honestly, not being mean, but you do seem very confused by the visa and how to go about it so I seriously recommend you speak to agent to help you navigate this.
Your assumptions are incorrect. The length of time your $$ needs to be banked depends on what embassy you at thru. The 5 year period starts the day the visa is issued. When you enter, you'll get a stamp that is valid to stay for 180 days. You do not have to leave every 90 days... no idea where you came up with that little nugget of wisdom. You do need to file a 90 day report. It's multi entry, you can leave and come back getting another 180 stamp on entry. You can apply for one extension per entry by proving that you still qualify for the visa... basically you need to resubmit all the original documentation including treatment plans, course, proof of remote work, etc, as well as providing proof of finances. Wouldn't normally recommend an agent but in your case getting some assistance might not be a bad idea.
This group is specific for DTV so you might get a better response from one of the regular Thailand Visa Advice | DTV | Retirement & More or Thailand Visa Advice QA groups since you are applying for a Non O.
Applied thru Vancouver consulate end of July 2024, remote work as a company owner and dependant. Submitted company's registration, tax return, letter approving remote work, personal bank statement. Main DTV holder was approved in 2 hours. Submitted for dependant with copy of main DTV, marriage license, bank statement approved in less than 24 hours. Joint bank account so balance had to be 1M THB.
No questions on entry in August. Left and came back in October, no questions. Previously here on Non O retirement but had been out of Thailand for a year.
It's unfortunate that pretty much all social media platforms have trended this way in the past years. Since there are no consequences to bad behaviour people feel free to be bitter, nasty and plain old mean. Add to that a lot of people don't stay up to date on entry and provide their advice based on something that was in force a couple of years ago, can't mentally adapt to the fact that Thailand is changing and implementing stricter policies or they are just upset that the DTV actually exists. It's the just because they've never been hit by a bus doesn't mean it never happens debate.
Then you have the people asking questions who don't like the answers and get nasty which just circles back. I'm not innocent in it, I try to give advice based on my experience but when someone comes back at me and tells me what I actually experienced is incorrect, well it can be frustrating when you've taken the time to provide an answer. My personal favorite is when people post a question, get the same answers on what to do and three hours later post again saying they did the complete opposite of what was advised and have now run into a problem 🤷♀️ .