3. not sure what models you are refering to. did you try opening one up in a model viewer program? there was no special 'ritual's engine multiplayer'. the MP side of Condition Zero has always been the standard CS mod, wrapped into a different package and using a slightly different .exe file.
The models he means are present in the czeror/models/player folder... m1-arctic.mdl, m1-gign.mdl, m1-guerilla.mdl and m1-urban.mdl. They are only about 700kb each and only contain one type of head/body texture unlike the others that have from 2 to 5 different styles...
Perhaps they are another example of files that have not been removed when the game was released...
Cheers for now