You really are moving way too fast, quiet way ahead yourself. Truth is that you seem to be desperate and you don't understand exactly what you are talking about.
So take a deep breath, slow down and look around you till you see the real world.
Antway, Linux/*nix is the favourite for the hackers out there on grounds that it gives you alot of control over your machine which you will need if you wanna start this art. BTW i know a friend who uses windows for his hacking adventures n he is good.
Backtrack/Kali isn't neccesary as a base system n you should realise it aint gonna make you the next black-hat-hacker the whole world fears. The only advantage is the drivers that come packed with it may get the Job better done than you usual distro. For the tools, alot of 'hackers' prefer to build there own arsenal and install only the tools they prefer n use which makes them easy to twick rather than the 100s of tools on BT/Kali.
So i would advise that you move around in any Linux shit , hell even*nix shit like *BSD till you find your favourite, learn hacking slowly and install only the tools you understand and get the Job done.
About KDE and Gnome, still sure you maynot even know what those are, but yet still you also have to find your own favourite. In this world, you man up and be your own man, make you own dicisions and be yourself. Its the only free world without ruthless deception(except honeypots, please stay away from those.
Happy hacking~!