There are a few possible causes for the "appear as errors" and "No hales use any sound" bugs
sv_pure is set to 1 or 2 and the models/sounds aren't whitelisted. One way of testing this one is to see if there's anything in the games download\models\freak_fortress_2\ folder: on 64-bit Windows, that'd be C:\Program Files (x86)\Steam\steamapps\common\team fortress 2\tf\download\models\freak_fortress_2\ by default. If there aren't any files there (or the directory doesn't exist), then it's likely the next problem instead...
The models/sounds aren't being downloaded by users... either they're missing from a FastDL server or they're not in the correct spots on the server.
As for the other errors, you may want to make sure you have one of the 1.6.0 builds of TF2Items to make sure that's not part of the issue. The 1.6.0 release wasn't changed on the main TF2Items thread until February 2014 despite it being mandatory since July 2013 in order to properly remove attributes.