What are the requirements and process for obtaining a 3-month Non-Immigrant O (Marriage) visa at the Thai Embassy in Vientiane using the eVisa system?

I have a couple of questions related to obtaining a 3months Non-Imm.O(marriage visa) in Thai Embassy in Vientiane.

Firstly, after applying through evisa sytem being in Vientiane, will I still need any official applications in paper as it was before to submit to thai Embassy in Vient.,or not?

Secondly, should I make the payment of 2000baht for the visa through the Thai Embassy in Vientiane before applying through evisa and attach that payment to the official evisa application?

Thirdly, How long(how many days) usually it takes for embassy to issue that visa if everything is in order and accepted by the immigration in Thailand?

Fourthly, is the any financial requirement (how many thousands baht) should an applicant has in his Thai banking account ,if any?); and,if this financial proof should be issued by the thai bank or it is enough to attach the copy of the bank book to evisa application?

Furtheremore, I live in Thailand for many years on Non-Imm O visa(marriage visa), but it will be the 1st time when I need to go to Laos to apply for this type of visa using eVisa system,and this is why I ask so many questions.

Kindly let me know with all detailed and current requiremnts.

Thank you so much for any piece of inf.