Is there an easier way to add an existing user to a new project or existing project?

All of our staff are registered with Zoho Projects now. When we create a project and need to assign staff to a project, we need to:

1. Create a project

2. Go to all members, and manually edit which staff can access this project. 

Imagine if we have 10 staff to invite to 1 project, how much time we would waste it on inviting them. 

Why not just assign them to a project like what you could do with when you creating a task.. You can just assign which staff is doing this project. Done, easy. 

Also, when can we actually delete a project?