depends on what youre trying to do, whats in your init.rc, whats in your init.qcom.rc, what your device variable is set to, etc
uevent you probably wont need to screw with. usb is probably unnecessary unless you wanna put in custom crap, the qcom one will handle that stuff
as far as the init.warplte.rc goes though, if it is used, and that would depend on the init.rc, you would put init.rc commands that arent in the init.rc in there, proprietary things, mount commands, things of that nature. its only purpose is for you not to have to modify the init.rc directly, you leave the init.rc built by cm or whatever, then the import init.${device}.rc or whatever is called, i never remember the correct import syntax for that but youll see it, that line calls the ro.device variable, say its "crap", and combines the init.crap.rc with init.rc, making them one file essentially
as i said, the bare init.rc made by cm or pretty much any android build will not have mount commands, so mount commands are put into a secondary init like the init.qcom.rc or init.warplte.rc, proprietary things go in there like special zte startup commands, things like wifi that need adjustments go in there, but its all up to what you want and what you need, it and the init.rc are individual pieces of the same puzzle, what the init.rc doesnt have and you feel you need you put into the init.whatever.rc