I am trying to Install Unnecessary Violence and it says it requires NifScript. Does it need the actualy old version called NifScript or will NifNE, the newest version, work fine?

It requires the old NifScript version to work.

If you don't use Deadly Reflex, you can use NifSE + the DUMMY NifScript file, both available http://code.google.com/p/nifse/downloads/list. This allows you to take advantage of some of the new features in NifSE (like not causing hard-drive bloat) while still using NifScript. However, this version of NifSE is incompatible with Deadly Reflex 6. If you want to use both, you'd have to use the DUMMY NifScript from that link, and use the version of NifSE that's on TES Nexus (which hasn't been updated because I don't want to break compatibility with DR6 without giving Skycaptain a chance to respond).