Is it possible to view the total costs of all contracts I am working on even though I have not yet produced an invoice?
You can create a custom field defining the various contracts and than use sales invoices by custom field.
The answer to your question depends on what you mean by “total costs of all contracts,” as well as what type work you are performing. If you are billing hourly, you can use the Billable Time module. The uninvoiced value of work in progress will be found in the Billable time - movement account. You might also use tracking codes to separate income and expenses by contract. Payslip items might be used to track labor costs of employees. Without more information about your circumstances, it is not possible to give a firm answer.
Sounds like another job costing feature request?
Yes, if you use tracking codes when recording the costs.