lots of questions but ill answer at least some of them...
1.yes your major will, to some degree, offset your low (but not terrible) gpa, as will the fact that since returning you've preformed much better, you SHOULD strees your interest in the field, if you have'nt already - law schools view your type of major as 'sexy', as I've heard it called before.
2. It IS awful late and you should do whatever you can to speed up the process with recs, etc... have you thaught of waiting another year, if at all possible and being early for next?
3. DON'T be afraid to apply to Washington University, I think you would have an excellent chance there (I've been accepted there btw), probably more so if you could bring up your lsat even a lttle bit (asssuming you apply next year) - I don't know much bout STL U but if you want to stay in the city, Wash U is certainly the way to go, if you can swing it.
4. No, financial aid will have no effect on your acceptance/rejection.
5. Lastly, you should DEFINATLEY write an addendum explaing your academic incident, don't make excueses, just explain it honestly. You should probably also write (in the same addendum or a different one) you're unique situatiuon - age, job, life experiance and why you're a different student/person than you were in the 70's.
hope that helps