The LHC has an off chance of indicating that some predictions may be wrong, but it's a long shot that an experiment in the foreseeable future will conclusively say one way or the other. So while you're right that string theory has given more equations than "god did it", it doesn't give us all that much more to test, which is the problem.

You're right that the LHC has an off chance of verifying (indirectly) some predictions of the theory (microscopic black holes, sparticles, super symmetry (of the breaking of) etc.), which is good, but I'm not aware of these "cracks" in the standard model that you mention unless you mean gravity, which is more of a limitation. Otherwise, the standard model has demonstrated some of the most spectacular agreement between theory and experiment in the history of science AFAIK.

String theory makes predictions a plenty. The problem is that non of them are testable in any direct way. So, the main problem with the theory is a lack of falsifiability (see: not even wrong).

String theory is ripe with predictions. The problem is we can't test most of them directly, hence the main problem - lack of falsifiability (see: not even wrong).