These pictures are difficult to really critique but I'll give you my novice opinion.
The buck: I can't tell if his chine is dippy or if he just looks that way because he's reaching above him for a branch. Otherwise, my personal opinion of him would be that he needs a bit more heart girth and a better front end assembly (much deeper brisket). I can't really tell how wide he is from a side shot, would have to see him walk. The same is true for his rump - is it steep, is it just right? Hard to tell from this shot. His coloring on his front legs misleads me too.
The four-year-old dry doe: Again, I can't tell if she has a dippy chine and/or high withers. I suspect high withers (which is not necessarily a bad thing). She has a nice brisket, decent heart-girth and spring of rib, and good rear leg angulation. At first if you cover her tail, I think her rump looks about right here, if not just a hair steep, but when you include the tail in the picture, it accentuates the steep rump because of the low set. I'd like to see more bone on this girl and more upright pasterns on the front legs. It's hard to tell from this shot, but I think I'd like to see more of a roman nose on this girl too. She appears to have a nice, flat bone pattern, though.
What, no shots including udders? Are all your girls dry? You must be missing the milk!

I'm about to dry my girls and I don't know WHAT I'll do without the milk! lol
Heidi: Hard to judge with the way she is standing but she looks like a yearling so that fits. Nice bone on this doe, fairly good front end assembly, and a nice, uphill stance flowing evenly to a level rump. Her rump really isn't that much better than the four-year-old, but because Heidi's tailset is higher, the rump doesn't look as steep here. I'd like to see more spring of rib and better rear leg angulation, but these things would be easier to judge with the addition of a top-down or rear shot. Nice upright pasterns on this doe.
Lyric: Pretty similar to Heidi in many respects, but appears to be more mature. What's her age here? You are right, she is too stretched out. If the front legs were set more squarely beneath her shoulders, she would look to have a better brisket. Similarly, the back legs wouldn't look so posty. It's hard to tell for sure with this shot, but I think her back legs are a little posty in actuality since I've seen many goats standing like this that do not look as posty. Could just be where her weight is distributed, or the angle of the photographer, though. The second shot of Lyric shows nice, upright pasterns on the front end and the brisket I knew was there that wasn't showing up in the first shot. Her brisket still is a bit shallow, but not bad. I'd like to see a stronger jaw and a bit more of a roman nose. My complaint with this shot, though, is that the top of her front legs looks a little odd - I think it's the angle of the shot because you don't get the same effect with the other goats' shots. She does appear to be fairly narrow on the chest floor (common in this breed, I understand), but I think I would have a better appreciation for the whole package, really with all your goats, if they were holding their heads properly so we could look at the shoulder and neck tie-in. They all appear to have fairly upright shoulders, but it's really hard to evaluate this with goats holding their heads this way. Don't fret though, some of my goats HATE to hold their heads properly when walking or standing in line.
On the issue of a dippy chine, you might try finding a nerve farther back on their spine to ask them to scrunch. It almost looks like you are pushing their chines down inadvertently.
Of course take this all with a grain of salt - I'm still very much a newbie.