I need advice about legal documentations! Please help!!!

I am 18 years old and is a Canadian citizen.

I am currently in Vietnam for the summer and would like to bring my 12 year old brother (also Canadian) and my grandparents (Vietnamese) to Bangkok Thailand for 5 days for tourism.

For my 12-year-old brother:

Are any parental permission documents required for him to travel with me?

If so, must the original signed permission letter be presented, or would a scanned/digital copy be sufficient?

Is a birth certificate or any additional documentation required for him as a minor?

Visa requirements:

Do Canadian citizens need a visa for a 5-day visit to Thailand?

What are the visa requirements (if any) for Vietnamese citizens traveling from Vietnam to Thailand for tourism?

Do you agree? More tourists are going to Vietnam than Thailand because it’s cheaper?

Seems that Thailand is a stable as ever.

Just heard the Thai government are not changing the entry stamp from 60 to 30 days, as due to the low tourist situation ,they don't want to rock the boat

How long must I stay out of Thailand after a 90 stay?

So, please tell me is the 60/30 days free entry over now?

Is this a good time to go to Bangkok? I’m looking to spend a couple months in Asia.. was thinking of Vietnam 🇻🇳 instead since the earthquake. Thoughts?

I had been seeking a way to get QR Scan pay in Thailand as a frequent short time tourist.

I think I've found the solution outside of having a bank account in Thailand. For me this is a bridge that will settle me till I move to Thailand. It looks like they are expanding availability now into malls. Previously you could only load at the airport. I hope more banks start going this way. Tag thai Easy Pay.

What are the neighbouring countries I can tour while on DTV visa?

Can I, as a tourist, come and stay for 60 days, go to another country after that, go to Thailand for another 60 and keep doing that? How often is that allowed