When I first started to look into b&w for landscapes, I soon realised (even before I took the photos, and they were on film, so no instant feedback to check up on one's work right away) that I had to LOOK differently than I would for colour photography. Upon wandering around looking for motifs, I had this distinct feeling that anything too little contrasted (even to the eye) would NOT look good in the photo. As it happened, I was looking for motifs in the same season as we are in now. Lots of bare trees. THOSE, I thought were quite nice subjects given there were only light grey skies to be had for most of the time, too.
Having said all that, I get the feeling that with your 1st and 4th photo you have found something that renders itself nicely to black&white, while the 4th may still get some more contrasts.
And that moon photo will look pleasing in both versions, I think, only do I find the moon to centred, but there is so much room for some cropping that that is a minor thing.
The 2nd and 3rd, however, are the ones that are definitely too busy and too black in the shadows (we don't really see the little statues' faces). And I guess more things could still be recognised in those two when they were still in colour (?)
In these photos you cant see their face in color or B&W, i took some where you could. I liked the silhouette of them and I thought that it was better as a B&W photo. But it does seem lacking and too busy