You need to find out from your local Thai Embassy if they issue a dependent visa for a spouse and, if so, what visa you need to apply for (probably a Non-OA) to get one. You then decide if that's the route you take and get married.
if "anyone" can vie it then you can view it and look to see if it's possible to download your report to be printed or saved to be uploaded to the eVisa application
You wouldn't have your eVisa application assessed by the RTE London then so you need to consult the Embassy website serving the country for where you'd be applying from
because you cannot get a dependent visa from inside Thailand using a Non-O retirement visa. It is normally only issued if the retirement visa is a Non-OA which can only be purchased in your country of residence.