Hi Kola,
The estimate project is vast functionality and is related to advance project management. All your points can’t be answered here considering the depth of functionality.
However, i will put down some basic points related to estimate projects.
Estimate projects are typically used with fixed price project although it can be used with internal project also.
Whenever a FP project is created you can create a estimate project simultaneously. Project setup can vary and hence its related setup.
Estimates project are mainly used to post estimates for a project when duration is long. After the project is estimated, then only it can be eliminated which is like project closure.
Pranav…