One question came in asking basically whether people (in my "universe", of course) with super abilities can get such things as cancer or diseases. The answer is yes, absolutely. While most of those with super abilities have some degree of speed healing (including myself), we can still succumb to various diseases, most often related to our super conditions. In order to better explain our vulnerability to certain medical conditions, we must first discuss the origins of super abilities.
Theorists and scientists on superhuman physiology have two competing theories related to the origins of super abilities. Some say that they are the next step in the evolutionary ladder, while others say that it's a genetic mutation. There has been no set acceptance of either theory, because successful pairings of a human and a superhuman very rarely result in an offspring that has a super ability. Usually only pairings of two superhumans result in a superhuman child. The very low success rate for a human/superhuman pairing suggests a genetic incapatability, but if that incapatability is due to the superhuman's genetically enhanced DNA, or if it's due to a genetic mutation, no one has yet agreed. So basically, more studies are necessary.
That there are very few superhumans suggest that it is very difficult for them reproduce. Also, many of them die young - there are very few elderly superhumans, because so many of us live dangerous lives that end in our untimely demise, or because of health complications related to their super condition. For instance, those with super speed have to be cautious of wounds in which bleeding results. Depending on the speedster, they could literally bleed to death in less than a second - much faster than the fastest EMT could treat them. Those with super strength often take stupid risks with great weights that they discover to actually be beyond their ability to handle, and thus they are often crushed by the very weight that they sought to lift, because there was not another super strength person nearby, or heavy lifting mechanical equipment was not available when needed.
Cancer in superhumans is almost always fatal, as there is practically no research on superhuman cancers, because there are very few super humans. Such cancers are almost always immune to treatments that would help normal human cancers. In order to understand superhuman cancers, the origins of superhuman abilities must be discovered, and as stated previously, that is still being debated. Thus, if a superhuman's super immune system is unable to combat the cancer, then virtually nothing else can.
And last, for those with invulnerable skin, internal bleeding is always fatal if they don't have speed healing. EMTs are unable to cut through their skin to stop any internal bleeding. There are, of course, many other examples of health hazards related to super abilities and super conditions, but I think I at least provided a good start of how superhumans can be as vulnerable as humans to cancer and disease.