A physiatrist or neurologist familiar with PPS can perform appropriate diagnostic tests. The library of Polio Outreach of Spokane is a wonderful resource. Polio Outreach of Washington State also publishes such a list. Everyone's going to die someday, but not from post-polio syndrome. Again, the support group is the place to go for this information.
Many people can offer their experiences and the library has some great articles on the topic.
As you experience decreased strength, energy, and function, and a higher level of pain, you can expect to have to make some lifestyle changes. However, just as the severity of symptoms varies, so also the number and magnitude of lifestyle changes differs from person to person. The Polio Outreach library can give you more specifics. One approach to the whole issue of activity is to be kind, positive, and gentle to ourselves. The PPS Bibliography is a annotated, organized list of 1200 articles related to post-polio syndrome.