String theory is often said to be one possible way to a theory of everything. In that setting it must obviously not just encompass gravity, but everything described by quantum field theory also.
In particular it must describe the elementary particles and the three fundamental forces properly described by QFT.
It turns out though, that QFT is totally non rigorous when interactions are taken into account. String theory, on the other hand, as far as I know (and I can be totally wrong, because I've never really studied it) is a rigorous theory mathematically speaking.
So in a sense, string theory does solve the problems of mathematical rigor presented in QFT?
I'm not discussing whether or not String Theory actually describes nature considering things like supersymetry, the 10 dimensions and so forth. I'm actually trying to understand if from a mathematical standpoint the problems of rigor in QFT are solved in String Theory.
In other words: the interactions of fields described in QFT without any rigor can be recast with string theory in a rigorous form?