Orgelbüchlein - next cycle work you are well on the final straight!
I like them all, also from the darker registration. The "Alle Menschen müssen sterben" sounds not just resignative from the composition to me (what one could think according the title, translated like "all people must die"). Instead more happy - the death was nothing one has to fear for in Bach's religion.
I know I tell always the same, but the Orgelbüchlein pieces have MUCH reference to the underlying lyrics of the songs. It is not too bad to indeed sing along the piece in order to get a feeling for that, just my opinion. When Bach wrote fermatas in the end of a line, just at the place one breaths, one really should breath with the playing too (articulate). We discussed that already, and you have other opinion, but especially "Jesu unser Heiland" would sound better if not played without breathing in a row. Nethertheless, it sounds better as my take to me - that was the first organ piece I recorded and after listening I feel deep need to rerecord (I rushed in places), whereas you have strong feel for rhythm and momentum.
The "Christe, du Lamm Gottes" piece is not just the difficult one, but I could swear you recorded it just from sightreading without longer practise. There are some spots which are a bit uncertain to me.
Beside that little niggling it's all in all very well - what for a diligent musician you are on organ and piano!