Thanks for your answer and help and sorry for my late reply. I didn´t notice that someone reacted to my post.
Here are some pictures of pass 1:
I don´t know which calibration plate exactly I went with in the end but I found some settings that now work for me for this particular model.
I started with the generic profile and since it didn´t work I installed orca and did the manual calibration procedure.
I also tuned down the number of walls (I had them set to a number so the model is solid) so there are not so many small areas to fill with short extrusions which caused stringing and blobs. Instead I used 3 oter walls and 100 % infill to fill the model where the printer fills the model in longer continuing extrusions.
What orca seems to ignore is the setting to print only one outer wall on the top surface. For the first layer this setting is applied in the slice, for the top layer it is ignored and it always prints the 3 outer walls.
So far I have only printed this model in PETG so I don´t know yet if these settings would work for other models too.
Also Bambu sent me a new nozzle and extruder but that didn´t make any difference. I cannot use the first layer inspection and automatic flow calibration reliably because the nozzle always looses some filament while the printhead is traveling over the bed to do it´s scanning stuff and sometimes it carries a 5 cm long string of filament out of its cleaning station. If I´m lucky, everything works fine and the dripping filament gets lost somewhere outside the model. If I´m not so lucky it end somewhere in the last layer and the nozzle crashes into it while printing the following layer…