Questions about the A8 2.8 D2

Hello dear A8 fan community,

my name is Chris and I'm at home in the beautiful Upper Allgäu. For 10 days I have been the proud owner of an A8 2.8 (AMX) Quattro with 142 kw, Bj. 01 with 82,500 km and 5 gear Tiptronic.

The predecessor vehicles were a 100/C4 2.8 Quattro and an A6/C4 2.6 Quattro. Both were hand-operated and very good vehicles.

Now I've made a little bit of a smart in this forum, and I've always noticed that there are some problems with the subject of gears. Now that I have been on the phone with ZF in FH, I would have a few questions about the subject of gearboxes, as I have not received satisfactory information from ZF.

1. I really have to worry about the condition. The durability of the gearbox make me think? Do you have any special experience with this transmission? The car was treated very gently by an older man and was also driven accordingly. The top condition speaks for this both technically and optically and driving or rather gliding does it perfectly. The transmission switches softly in both operating stages. All service included. Timing belts made.
2. Where can I find out in the operating manual what kind of gearbox was installed here and whether it is running with a "lifetime oil filling"? What's a possibly. Code for that?
3. I was told by ZF that an ATF oil change should be made at 100.- 120,000 km. Does that make sense if there are no noticeable problems? I realize that care and maintenance must be and should be. But I also think "never change a running system"...What do you think of the following statement that I found in another forum: "There are two measures that can be taken to protect your gearbox. First you exchange all 80tkm of the ATF with sieve and incl. Slide box revision (make everything at ZF in Dortmund). Second, you install an additional ATF cooler with thermostat. When you check the air mass meter and the coolant temperature sensor every now and then, the gears also hold 300tkm and more.
4. Can someone please tell me a competent workshop for such a transmission inspection in the Allgäu/Oberallgäu. Audi/VAG is out of the question for me due to bad experiences and ZF in FH no longer do it. There are only heavy vehicles to be looked after. Saarbrücken or Dortmund are not exactly the next way for me either.
5. What else do I have to consider with the car (care, maintenance, etc.)?

Furthermore, the Navi Plus is in the vehicle to which I currently have the Teleatlas CDs BRD and Western Europe version 2003/04. When setting navigation with the CD of Germany I can not enter a road and the CD of Western Europe is basically not possible. Is it because of the CDs or does the device have an error? If it can be due to the CDs, which one can you recommend?

I hope not to bore you with my questions, but it is my first "dicker" and accordingly I lack the experience here. Thank you very much for your help in advance............

Greetings

Chris