Am I taking a wrong approach while looking for an academic position in applied areas - brutal criticisms appreciated!
If you are making a mistake, it may be in narrowing your focus, closing off opportunities. Especially if it is you who is giving a too-narrow definition of your capabilities.
A math PhD should be able to teach (nearly) any undergraduate math course and many MS level courses. Every college and university teaches math and so needs people to teach those courses. The market is enormous. But for, say, medical imaging, there are few places that are truly interested. While it is also true that your skills should, and do, enable you to work on a vast range of problems, if you exclude those from consideration, or seem to, then your opportunities also close.
In a lot of ways a mathematician is like a Swiss Army Knife, being able to attack many problems, pure and applied, since they have a facility with abstract thought and how things fit together synergistically. But be careful, in any application, that you define yourself in a way that is flexible enough that others can see your potential.