Great that you rejoin the contest!
I played this Fugue recently as well, including the Prelude. The Prelude is actually my favorite of the eight (together with the first one). Musical taste is a very personal matter :-)
And I play the fugue with 8', 4', 2'. Your registration works great as well. For me that's the beauty of organ music: so many possibilities for phrasing, articulation and registration in just one piece of music...