This improvements are recommended for PvP (Player versus Player) in Nether.
First of all you have to find the gamefolder with his configorations.

Steam-->SteamApps-->common-->Nether-->Game-->NetherGame-->Config

• Disable mouse-smoothing
  Open "NetherInput.ini" with a Texteditior. Search the line "bEnableMouseSmoothing=True" and change it to "=False". Now there should be a raw mouse input for better and faster aiming.
  
• Disable motion blur/radial blur
  Open for this step the "DefaultSystemSettings.ini". Search for "AllowRadialBlur=True" and "MotionBlur=True" and turn both into "=False".
  
• Disable DOF (optional)
  Still "DefaultSystemSettings.ini". To disable DOF ("Depth of field") for a clear view search for the line "DepthOfField=True" and again change it to "=False".

This ini changes makes the battle against other players much easier!

Cash and experience isn´t a hard challenge in the game but money is always nice!
To farm fast cash and exp just go to the Trainyard or Tower Outpost (Wasteland). The only thing you have to do is just bring 2-3 packages from TYO to TTO or from TTO to TYO.
Best route is shown here:

There are many usefull skills in Nether... and there ´re underdogs too!
Like the "High Jumps"-skill. This skill is unlocked at LvL 4 and let you jump just a bit higher but this little difference is incredible! There´re many spots in the city where this skill is needed (firestairs, fences, cars, rooftops, steps). It´s one of my favorite and recommended skills in the game.

• PvP-Build (recommended)
  
  
• Anti-Nether-Build
  
  
• Objective-Build
  

If you´re heavy loaded it´s better to be somewhere around the big safezone (Lakeside). Sometimes it can happen that you accediently die (fall damage, don´t know how to use wings aso.).
While staying close and you die just spawn in the safezone and sprint to your stuff. With a little bit luck nobody else found it before you did.

It´s not wrong to stay in a small group to cover you and your allies. Playing with some other guys is recommended in nearly all MMO-Survivals.

It´s still not possible to change all keybindings in Nether.
To be able to do that just go to the gamefolder configs:

Steam-->SteamApps-->common-->Nether-->Game-->NetherGame-->Config

Search the "NetherInput.ini". There you´ll find a full list of all keybindings. Customize it to your style.

Buy water bottels to keep your health regeneration on. They´ll fill nearly 3/4 and costs just 75$.

To disable the ugly safezone lens flare effects just go again in the "DefaultSystemSettings.ini" and search for "LensFlares=True". Just change it to "=False" and the game is more enjoyable.

Many players don´t know it but it´s possible to split items directly in the inventory without the reloading trick from the earlier version.
Just drag an item while hold left mouse button and right click to release 1 item.