Okay, you can apply for a new Extension of Stay based on what ever reason, if you do not meet the requirements, your application will be NOT approved and get 7 days to pack your bags and leave the country.
That is not a tourist extension, but it will give you some time.
You can not apply for or get a Tourist visa inside Thailand. I have no idea what you mean with a working visa as such thing does not exist in Thailand.
You must have a Working Permit from the Ministry of Labor and a Visa or Extension of Stay that allows working in combination with that working permit. Two different things.
The under consideration period will be cancelled when you leave the country, no problem to leave without telling the Immigration Office that you are now able to travel.
If they used a German Passport to enter the country, the 30 day Visa Exempt Entry can be extended once with another 30 days based on tourism at a local Immigration Office.
Yes, some offices allow you during the last 45 days, others during the last 30 days of your Admitted to stay, to apply for the Extension of Stay based on over 50 years of age,
There are requirements to meet, contact your local Immigration Office for a hand out.
As there is no mention about the region where you have to apply, best option is to contact your local Immigration Office and ask for the hand out with requirements,
There are small changes, like hand drawn map or google map, depending on office.