It seems to me that your question is worded somewhat unprecisely, that may be one of the reasons for the lack of answers. You seem to be under the impression (apparently after watching "historic" entertainment programs) that the "Nazi Party", the NSDAP had some sort of a role in the development of "Nazi Super Weapons".

First of all, many of these "super weapons" are hyped up by certain American TV entertainment, apparently that stuff sells rather well. It is true that the period from about 1920 to the end of the war was a period of rapid technological advance in many countries, and many especially brilliant minds were in Germany, especially in the areas of aeronautics and internal combustion engines.

This was the case long before the NSDAP took over power, but they realised that advanced weaponry is important if you want to go to war. Thus, there was political support for engineers and scientists who worked in fields that were interesting to a war effort, and there were enough resources for them.

Hitler himself seems to have had a bit of an obsession with what the History Channel likes to call "Super guns", spectacular weapons that were never seen before. He ordered the development of all sorts of spectacular, often borderline nutjob weaponry like giant trains, giant guns, giant rockets, giant ships etc.

Some of these things were built while others were not. Of what was built, many things were successful, but many also drained enormous amounts of resources while offering very limited benefits on the actual battlefield.

But the development of these things was ordered by Hitler himself and/or some of his very close subordinates, and conducted by "ordinary" scientists who often had no close links to the NSDAP.

The statement that "the Nazi party was responsible for this or that super gun" is a gross oversimplification of the war effort in a dictatorship.

edit: I just had a shower and came up with a much better way of wording this: Saying "The Nazi Party developed this or that" is a bit like saying "The Democratic party developed the SR-71". In reality it was developed by Skunk Works, a military-civilian organisation, with direct development orders from a government agency during a time when Kennedy, a Democrat, was in power. Similar things apply to these "Nazi" weapons, which were not "Nazi" (as in "of the NSDAP") weapons, but weapons which happened to be developed during their rule.

Speaking to small arms design, the Germans and particularly the Nazis designed some fantastic weapons that were copped and are still in use today. In particular the P-38's action was directly copied in the Beretta Model 92 which is now the M9 in the United States. The M60 borrowed heavily from the FG 42 and MG 42. The MG 42 was copied by other nations as well and some are still in use today in particular as the MG3 with the German army.

While the Nazi's can't claim it's complete development the K98k has been used extensively by other nations, especially the 8mm cartridge. Many European nations produced or purchased a derivative of the K98 rifle. The Mauser action is the basis for nearly every hunting rifle on the market today, notably the Winchester Model 70 and Remington 700 rifles.

Some even argue that the STG 44 was the basis for the AK-47, though this is largely speculation. Mikhail Kalashnikov himself insists this is not the case in an interview on "Tales of the Gun"