Although you have green grass, it looks mighty short, not even close to covering the hoofs on those heifers, I would have started feeding them hay a good while back if they were mine, a worming and a good free choice mineral program might help too.
Not all your problems are bull related, although he's not helping matters. For instance, a lot of the young heifer's structural problems come from her dam side, but, again the bulls not helping any either.
Your choice for a AI bull should help you out some,
he is better that what you have, but I personally don't think he's a world beater either. The Pinehill bull that's linked may help you some, but he has some of the same structural problems some of your cows have, if you plan on retaining them all. The cows do appear to have some depth and a decent amount of bone, it's something to build on with the right bull. Ya'll still seem to be using the larger framed Herefords which is kind of surprising.
I like this one, although I know nothing about him.