• Can you rename or edit the ticket “stages” i.e open, active
Yes - you can rename anything using the translation tool available in admin control panel.
• Would it be possible to import a complete project by customers with all its different tickets?
It is possible, but a custom import module would have to be written for that. If 2 companies are using EPESI for project management then it would be possible to setup not import but data synchronization between these 2 instances. This is something that we plan to introduce in the future - EPESI to EPESI data synchronization/exchange.
For now we have Premium/Sync module: http://www.epesi.org/Premium_Sync which was developed as a simple API to access data in EPESI.