I don't know if there is a generally accepted answer to these questions, but I'd like to try anyway.
What is the definition of 'skepticism' in relation to alternative medicine?
And a more specific question. Does skeptics have any positive claims about alternative medicine? What would it take for a skeptic to accept alternative medicine as a helpful way to treat illnesses and diseases?
There was an acupuncture question recently. Some of the answers there may have "positive" aspects.
Skepticism has many definitions. On this site, we apply "scientific skepticism". Wikipedia defines scientific skepticism.
Scientific skepticism (also spelled scepticism) is the practice of questioning whether claims are supported by empirical research and have reproducibility, as part of a methodological norm pursuing "the extension of certified knowledge"
The article goes on to give more context. That's as good a definition as any. This is not related to alternative medicine - just a general definition of scientific skepticism.
Does skeptics have any positive claims about alternative medicine?
It isn't clear what it means for skepticism to make positive claims. It is a process of questioning claims. Scientists may make positive claims.
What would it take for a skeptic to accept alternative medicine as a helpful way to treat illnesses and diseases?
We have mechanisms for testing whether treatments are safe, effective, efficacious and cost-effective. Treatments that pass these tests are considered part of medicine.
Calling a treatment "alternative medicine" is often used as a technique to paint the treatment as medicine, when it hasn't passed the tests (or even has failed the tests.)
When an alternative medicine is accepted by science as a helpful treatment, it is no longer called alternative medicine. It is called medicine.
