Drop Table, Variable Name, and Query Bug Fixes

One line drop all tables was not working well. Replaced with individual
drop table lines for every table.
Some tables had "firstName" while other tables had "fName". Made them
all "fName" to fix issues in queries.
Query 4 required the columns in the select to also be in the group by
clause.
Query 6 needed to have the MAX function pulled out into a separate
query to get the max on all the counts, not just one.
Query 8 needed to be a join between 2 tables to get the patient name
and furure visit date.