The buildings you mention are from multiple web sites. But the comments apply to them all. As fern mentioned, do not run any user created patch programs. They are known to cause sporadic game crashes. Some change Zoo Tycoon files directly. Some copy Zoo Tycoon files and make changes. But both techniques can cause sporadic game crashes. If any patch program finished, I would recommend that you copy the Zoo Tycoon lang0.dll back from the Zoo Tycoon CD-ROM. Also, do not put any user created ".dll" files bigger than 1.8 mb into your Zoo Tycoon folders. If you did, they should be removed. These also can cause sporadic game crashes. Also, I would not run any user created "setup" programs since some of them also run user created patch programs.
As fern also mentioned, there are warnings on the download pages at ZKL for the downloads that have problems. It is important to pay attention to those warnings and to follow their advice.
I do not know what you mean by them "not loading". If you mean you are using the button inside Zoo Tycoon to try to load user downloads, you should never use that button. That can also cause problems, especially when you want to remove something later. Instead, you should copy ".ztd" files manually to the Zoo Tycoon Updates folder or dlupdate folder. Many of the things you listed will work in Zoo Tycoon this way. They will work even without a ".dll" file, although then their messages will not show up in Zoo Tycoon. But many of their messages are in LANG--ZKL.dll and ZA's combined ".dll" files. However, some ".ztd" files have other problems. Again, those at ZKL will mention those other problems.
Good luck with your downloading.