No bad for a first......
1) Your head/neck/breast juncture needs to be more of a smooth transition. You can easily do so by pulling the skin forward from the breast toward the head.
2) Look at your top wing compared to the bottom one. The top one has a nice shape but the bottom one looks almost straight. A ducks wing usually has a bend in it....think boomarang shape.
3) The tail feathers are too flared. Tone that down just a little the next go around.
4) The wings would also look better if they touched the body....without the gap. Wings angle backward....not forward so that would cause there to basicly be no gap between the wing and body.
5) You can get your wing feathers (primaries and secondaries) to overlap properly by using painters tape. Cut a piece the length you will need (do the primaries with one piece and the secondaries with another) and bend a tab on one end for easy removal. Start away from the body and run the tape underneath the feathers. Take each feather and place it where you want, stick to the tape, and let the bird dry for about 2 weeks before removing the tape. Once it dries the feathers will stay where you put them.
As far as the speculum feathers not laying properly and the barbs seperated.....every so often one will just be like that. I had one just the other day myself. All you can do is wash and rinse as needed. Sometimes feathers are just too damaged to "fix".
Keep up the good work