Managing task owners

Managing task owners

New to Zoho - Trying to determine if we can have a database of "task owners" without using their emails.  We are custom builder and are not trying to communicate directly with our subs via zoho project / email but need to schedule them.  Also - how do you edit a name - looks like it only pulls the first part of the email. Also is there a way to categorize skill level for users?  In this instance we would have users classified as painters, tile, sheetrock, etc. 

Thank you,

Kathy Neill
Reynolds Signature Homes