It sounds very similar to what is required here, but if you are over seventy then no language exam is necessary. There is a huge programme underway of getting documents via the internet at present. My wife has just renewed her driving license that way, free of charge by the way. There are big changes underway to centralise documentation. Previously it was all done on a departmental basis, and the same set of requirements were interpreted in different ways. Over the past two years the requirements are at last making more sense.
Basically the requirements in Germany are:
1. Proof of 8 years continual residence
2. Evidence of 5 years of payments into the German state pension system (there is leeway on this one)
3. Proof of income for the 3 years prior to naturalization.
4. Proof of linguistic ability (if you haven't taken a professional qualification in Germany then you have to take an exam in the language) - I think they have the 70+ excemption as well.
5. You have to take the test 'Life in Germany', which doubles up as an extra language test.
6. Documents from the UK. Minimum would be a certified copy of the birth certificate - in my case they wanted my divorce certificate as well (this may have to do with the inheritance laws being different here) - or it could be a case of checking up on maintainance.
7. You have to take an oath to live by the constitution of Germany (done both orally and in shrift)
8. You sign an allowance for them to check up on your past with the inland revenue, for outstanding debt, and to check up with criminal records in both countries.
The actual admin. costs for processing the naturalization here are in the region of € 250 (this compares to around 1,300 pounds for the same process in the UK !) Dual nationality is allowed as long as the application was made before the event of a hard Brexit. The actual waiting period is relatively quick here - once I had given them everything required I received the letter of acceptance 2 months later with an invitation to the naturalization ceremony. As far as I can tell the process and requirements are different in different countries - my cousin has become Spanish, and had to give up his British nationality to do this. Also the Spanish language exam is set at a much higher level.