Extending a non-immigration visa with retirement motivation

[ravisto]

Hi everyone
First of all thank you all for sharing these precious information. Having read many threads I need just few  information to complete my situation , and that is:
1 - I am currently in Thai with a non-immigrant ED type visa, I have already read in previous threads that someone has already succeeded in ChiangMai to change the extension reason with a school letter canceling extension ED, There is someone who Did it also in Bangkok? I ask this because last month at immigration I got the paper with the indications to extend in the case of retirement and in the first place of requirements it is indicated "Applicant must obtain NON IMMIGRANT VISA TYPE O"
2- I have read about someone that asked the letter of financial support on the first floor of immigration at Bangkok Bank, someone know if also krung thai bank have a branch in immigration and can do the same (  the branch where i have the account is in pattaya and would be nice to avoid this trip)
3- I have seen also that in documentation requested there are  photocopy of documents with certified signature of the applicants: What means this ? The officer to which we apply can do this at the moment or we have to go in other office?

Thanks so much in advance!
gio