What is pro-rata insurance coverage?

Coverage A is the dwelling amount. As in, if it cost $250K to rebuild your house then that is what your coverage A should be.

Yes on Individual plans. Employer Groups have guarantees If you're denied as an Individual there may be a State Risk Pool for you http://www.nahu.org/legislative/HRPs/index.cfm

I can't remember. No seriously if you are in UK you can and depending on how advanced it is you may need a doctors certificate.

It means what the policy provides benefits for and how much. For more info www.SteveShorr.com

Yes, some states regulate the amount of coverage on a given policy.