I found a way of adding the Job Titles. You do it in the recruitment module (configuration sub-menu). It is also important to mention that you have to specify the number of employees that already exist for a Job Title before importing. After that, importing Job Titles in contracts will be a walk in the park. Note: if the number of people employed under a particular job title is less in the recruitment module than what is included in the contracts csv file you are importing, there will be an error.

You can import bank account numbers from Accounting -> Configuration -> Bank accounts -> Import
and job titles from Employee -> Contracts - > Import

These are master data which are required to be imported before importing employees.