Thank you all for your spended time and comments!
Juufa: Yes, Minden is in the northwest region of Germany, westwards from Hanover. And you are right, it is a protestant church, a village church, but nice (and heated during winter !!!). The more I play on the organ, the more I like especially this organ. Maybe anytime I don't need a light on to find every register...
Monica: You are right, the register offer much possibility for sound changes. But not easy sometimes to find a appropriate mix between pedal and manual(s).
Chris: Many thanks for your detailed comments. However, you are wrong: your versions are NOT shaky, and especially your "Jesu, meine Freude" is maybe slow, but much more elaborated regarding articulation. Everyone who tries this piece will see, how difficult it is to think on articulation for every voice because hands and feets have something to do (especially different things to do).
I think however, the tremolo is pretty decent. I am glad that this appears usable to me as some organ tremulos are really not usable (I also used it on "Oh Mensch, bewein dein Sünde").
Regarding pedal on "Jesu": The manual used only Principal 8' + Flute 8', the pedal Subbas 16' + Octave 8' + manual coppel to 2nd manual with additonal 2 x 8' registers. Simply have no more deep registers for the pedal
However, for my headphones the pedal part comes out sufficient enough, I think.
And, you are right, both pieces are like usual maybe slightly ruhed, especially the "gelobet" on some places. Maybe I rerecord this anytime, but if it is useable as it is you could take it to the site if you like.
Fast progress on organ? Only for the "Jesu" piece I practised 3 weeks, about 3 times a week, at least 1 and a half hour every time only for this single piece. That means about 14 hours + 3 x organ lessons. Only this piece, with only hands, only pedal, together, slow, fast so that it finally appears acceptable. A lot of sweat I think, for only 2 minutes time. However I hope to play it during church service in January, together with the Choral what people can sing.