The red lights in Thailand seemed longer to me, but really depends on the traffic.
How about actually asking a real question? Wait time for what? What visa? What is your passport country? Any other details that might help someone understand both the question and the details surrounding the question.
Yes, get a local plan. And it depends on the carrier, but yes generally wifi calling will be local.
If I were you I'd consider looking at switching to TMobile if it's practical. They offer free international data. It's not enough for you to not get a local SIM plan which you'll need regardless, but means you don't have to be scared of something going wrong and you getting a $1000 phone bill.
Just be careful. I know some people who got their SCB accounts with a work permit, and then when SCB found out they stopped working, they closed the account.
No, you're not paying for the visa. You are paying for the processing of the visa. Whether it's approved or not, they keep your money. No refunds. Just like everywhere in the world.
One is through a soft power activity in Thailand (Muay Thai, Thai Cooking, Medical treatment, etc).
The other is workcation, which means you are a full time remote worker and your company has specifically given you permission, in writing, to work in Thailand.