I'd like to take another stab at your questions.
1. Yes, 36 hours/week is often (but not always) considered full-time employment, with full-time benefits. Find out what's typical in hospitals in your area.
2. This depends on what your short- and long-term goals are. For entry-level staff nursing positions, prior education and work-experience outside of healthcare is often not considered - a new graduate nurse is a new graduate nurse. But it certainly adds to the picture of you as an employee and should be discussed to some extent during interviews. If you think you'll want to teach at some point, definitely go for the BSN. It is possible to advance in nursing administration/management with bachelor's degrees in other fields.
3. Some of your prior BA credits will most likely count towards your BSN but this will vary from school to school. Also check into second degree programs.
4. You can apply for student loans regardless of where you go to school -- federally-guaranteed loans such as Stafford are available for all post-secondary education.
5. Can't help you much there, as I'm on the other side of the country.
One other thought: have you worked nights before? If not ... and your prior work experience was all of the mostly M - F daytime variety ... don't plan your & your family's entire future around the idea of you working nights until you & your family have a chance to try it out. But you have a lot of time for that yet, and "reality" changes every few years as kids progress through different ages & stages.
Good luck to you!