
Dual citizen looking to get 10-year tourist visa
Hi, I am a dual citizen of US and Germany, and I live in Germany. I want to get a 10-year tourist visa, so I need to apply with my US passport. Therefore, can I apply with my US passport here in Germany? I would be applying to the consulate in Frankfurt, and my understanding is that I'll need to apply in person because these days they require your fingerprint. I have already applied there for tourist visas in the past with my German passport (I used a visa agency), but this time I want a 10-year visa so I need to use my US passport.
Also, I called the consulate in Frankfurt, and they said applying with my US passport "is possible, but no guarantee you'll get a 10-year visa". Therefore, I want to ask: Will I have a better chance of getting it if I fly to the US and apply there instead of Germany? Or are my chances generally not affected by where I apply for my visa? In addition, if I apply in the US, can I use a visa agency/service to submit and pick up my 10-year visa application?
Apologies for the many questions, but I've been researching this for many hours and haven't found any real answers. Your help would be greatly appreciated!