I just got a Razer Tartarus Pro and in addition I do have a Razer Naga 2014. Of course I also have a standard mechanical keyboard.
I have been using the Keyboard + Naga combo for some years now.
Now with the Keypad, shall I just ditch the keyboard and go for Pad + Mouse, or what do you advice me to use/configure??
Whatever is convenient for you. If you don’t need to type in chat, pad + mouse is a nice combo. If you do, having the keyboard nearby is fine, unless you type a lot, in which case keyboard + mouse is a better fit.
I usually play with a keypad + mouse (or with a controller), but always have a normal(ish) keyboard nearby for when I need to type. I have a wide desk though, and two screens, so if I need to type, I just swap screens, and turn towards the keyboard.
In the end, whatever works for you best is the setup you should go with.