String theory is just that... A Theory.
It cannot be 100% proven other than with the mathmatics, because the more we focus on the smaller elements that exist, the more we change them. So, without some sort of a spacial / time trapping device and a voyager of equal size to a so-called "string", it will maintain it's status as merely a "theory".
It would truly be interesting to live in the days of "String Fact", however I believe those days are a long way down the road, if at all possible.
Proof is not necessary if the mathmatics work. However, then it is merely "logic", which as we all know "logic" can be fallible.
If you're interested in Quantum Physics, here's an interesting read:
http://www.research.ibm.com/quantuminfo/teleportation/
It deals a little with the theory behind changing quantum level objects.
"According to the uncertainty principle, the more accurately an object is scanned, the more it is disturbed by the scanning process, until one reaches a point where the object's original state has been completely disrupted"
That article was written about a group of scientists working on a project by IBM on "Quantum Teleportation". (A very interesting read)
Anyhow, "String Theory" is very nice as a concept, and if it is indeed "factual", I believe it will open an entirely new type of science and new technologies for we as humans to explore.
In the Quantum Universe, EVERYTHING is possible as there are no boundaries but those of creation.