An Addon to switch between 2 keybindings (for bindings such as movement keys)?

I want to bind my movement keys / targeting keys differently depending on whether I'm playing PvP or PvE, and want to do it automatically.

I've downloaded Binder, but I can't get any version to work properly with 3.3.5. I might be using it wrong, but it looks pretty easy to use and I can't get it to. I'm expecting it to rebind my keybindings in the main vanilla keybindings list. I tried it using character specific both checked and unchecked. I concluded it doesn't work. Is there a working version to do this for 3.3.5?

Next I downloaded BindPad. This is excellent, and allows me to bind macros easily. But this only allows me to bind a key to anything I can do in a macro (which is great, but I want to do more than that). It doesn't allow me to rebind movement keys or 'target nearest enemy player' for example. I don't believe this is possible in BindPad?

Does anyone know how I can get this working?