Keeping a group “clean” is a difficult task, that you are handling well. I got some posts removed by the group admins too, I wasn’t happy about it but in the end there was always a reason and the benefit I got in this group is by far larger than my occasional disappointment. Keep the good work going, please. All the best with that situation!
if you have full 12 months of 65k coming in from a foreign bank account then you can extend your visa for another year based on this income and there is no need to keep the deposit of 800k on the bank after that
you could buy a cheap ticket from bangkok to e.g. Kualalumpur that is within 15 days and show that. Or another refundable ticket. or you get a ticket for 15 days and change the booking once you are here. But as the experts said: your airline might not let you board without that.
If you have a retirement income (Rente) then it’s much easier to get the visa in Germany. It can even be done online and you don’t need to have the 800K, just your Rentenbescheid.