[TomTom]

When you run ET standalone (Host) you are actually running 2 parts in one Server and Client. When you run ET and connect to an external Server you are just running Client side. Proper Bots (like Fritzbot) are server side, so the server must run the Fritzbot server DLLs. Now you can run a dedicated server in text mode on your computer. then run a second copy of ET (use a different directory) and connect it to your server (Host). That should allow you to then use other client side DLLs. You may have to deal with punkbuster and sv_pure 0. Anyway this is something I have only rarely done so somebody else will be better versed to answer all your questions.

And if your machine is fast enough you can run a combined server-client Host in one window and your non-fritzbot client in another window. Easier to set up and you can then compare the effects on the client UI etc.