Probably everyone saw these videos because Murdock spams #VU channel everytime when he does something... nvm. Anyway players have to put one file in Grand Theft Auto Vice City folder as you said, Zeke. I don't think that everyone will do that. For example if you wanna make a server with those NPCs you will need to add function which would be able to check if player has Murdock's addon or no.
I'd rather play with my bunchie than play VC-MP with bots...
Who said about playing with them? We just had a fun when "bots" were repeating GRAND's noob tactic. In any case they are useful because you can test what do you do wrong in glitching, sliding etc.. You can learn a lot with them and catch mistakes.