Thanks for letting us know which ones you are interested in. There are no problems with the double merry-go-rounds.
viewtopic.php?t=1199
Scenery-only (decorative) versions of the garden bench, Pizza Hut bench, stone bench, and Chick-fil-a picnic table already exist:
viewtopic.php?t=815
Although not the same, there is a different McDonalds Stand that works:
viewtopic.php?t=1227
As for the remaining things, now that we know what you are interested in, we can move those things up in our lists of things to do. That includes creating a guest hack that would allow all known user benches and tables to work, and one we would add to whenever another was created. That hack would be at DD rather than here or any other ZT site because the hack would have to account for things from multiple sites and DD represents multiple ZT sites. In the meantime, if you wanted to use a building only as scenery, you could put something in front of it (such as the Post and Rope Fence) to prevent it from being used. Just do not run any ".exe" or setup program or patch program from any of the downloads. The messages for the building might not appear in-game, but at least there would not be any problems.