If you change jobs will the new insurance company cover a dependent's cancer treatments assuming the new employer provides sufficient coverage?

Yes. For more information see www.SteveShorr.com/hipaa.htm

Group insurance through a job is the way to go. However, Diabetes is usually not a reason for not qualifying for health insurance. Your premiums will just be high. Michael FindYourPolicy.com

yes

Depends what the waiting period is. You would probably be eligible for COBRA in the interim.

Here are a few ideas: Some insurers write new companies, but not all of them will. You may have trouble obtaining insurance until you have a "loss record" or track history for an insurer to examine....