I don't have a beef with String Theory...
But I do have problems with the dogmatic approach of some of its practitioners. For the record; my copy of a green paperback by Green, Schwarz, and Witten is well worn, visible on the shelf from where I sit, and gets pulled out from time to time when I have deep questions. I especially like the intro by Witten on the lasting importance of dual theories, which was a motivating factor for developing the theory in the first place.
I am nowhere close to being an expert, but I did actually meet Ed Witten on my 59th birthday, when I also sat at the same table with Brian Greene. Unfortunately; I never got to meet Nima Arkani-Hamed, who was supposed to sit next to me. And since that time; I attended lectures by Marolf, Maldacena, Myers, and Strominger (among others). So I have at least gotten an overview from informed sources.
My recently-departed Physics mentor thought that String Theory was inevitably true but inconsequential unless researchers discover how it links back to everyday Physics in the known universe. This is along the lines of comments by Steinhardt, whom I met at FFP11 in Paris, back in 2010; and which I largely agree with. This kind of leads back to my earlier comment.
I am kind of wary of latching on to SUSY as a fundamental aspect of reality, especially after John Ellis's recent comments. I had a conversation with Frank Potter a number of years ago where he said that any number of unified theories could be concocted, that produce the Standard Model spectrum of particles, but also give us something else. His theory based on the Monster Group added another quark family, which has not been seen.
Not only Garrett Lisi, but also F.D. Tony Smith used E8 as a symmetry generator to derive a similar result. Tony claimed the LHC results validated his work by showing a triad of energy states for the Higgs. Unfortunately; Tony is no longer around to argue his theory. And another departed colleague Ray Munroe used both the Lie groups and simplicial geometry to create yet another theory with so called mirror-Fermions, which nobody is even looking for.
I think you may need to broaden your horizons.
All the Best,
Jonathan