Not sure about MTT, but if you are on a 60 day TV many immigration offices are requiring one to first get the regular 30 day extension before being able to apply for the 60 day Covid extension
In samutprakan (small amphur) they just took a copy of my passport in English my wifes housebook (she owns the house) and the application in Thai plus a bottle of JD - as they say every office is different.
For what its worth I used the web system on Monday this week for my 90 day report and it worked fine - approved on Tuesday. I use the Samat Prakan immigeation office.
It depends on the embassy. Some embassies will process tourist vasa without requiring you to be a resident (ie i know this can be done in Canada, but you cant get in there right now). There are reports of people getting visas from Turkey which is open, but I dont have first hand info.
you can not renew a visa. If you are inside Thailand you can apply for a yearly extension for stay off of your original visa, but that cannot be done outside of Thailand