Let's review:

Yes, this got addressed: "5329, page 4, exception 05 does not specify if expenses over the 7-1/2% are for the whole family or just the spouse who withdrew." The person whose Account this is has to have the qualifying conditions. Then, the Costs have to qualify (cannot be, for instance, Fat Camp). Then, yes, this got addressed: "IRS website Exceptions to The Tax on Early Distributions does not specify."

Because the Definition of "whose costs can you cover" and Definition of Dependent has been covered in Pub 502.

I gave resources to help you learn Whose Medical Expenses Can You Include, Who is a Dependent, and What Can I Deduct.

"I still can’t find out if the spouse can use the total $7800 which consists of the qualified medical expenses for the taxpayer, spouse and dependent."

It's all there in the Three Links. You have to read them.