Does this works also with CH RC4?
Yup, won't conflict at all, and it's my belief that it won't conflict with any other MODs whatsoever (barring any that try to do the same thing as this one) *
CH and other MODs like it change the way the forum looks or is laid out. LEV changes the required parameters for email address submission. This happens before anyone needs to worry about what the place looks like, first they have to get in!
Conflict with Signatures Control 1.0.0em - disables all user-verification in usercp_register.php. If you want LEV to work, remove/undo this MOD.