I have never found IB to be the source of the kind of problems you have
experienced. However, the project plan you describe is chaos to me, sorry
to say. To loose 10 developers onto the database, each making changes as
they need is scary. Planning and coordination are key.

We take the view that the database - structure and data - are a shared
resource which is NOT under the control of the application developers. We
have always assigned a developer to the role of "development DBA". They
maintain the scripts which build the test databases (and ultimately the
production DB). They coordinate all meta data changes. They control
field/domain/table naming to ensure consistency. The development DBA, if
they work carefully, can often spot problems with suggested changes before
they become critical. We have always done this and it has saved our
projects more grief than I can estimate.

We also build our databases from SQL text scripts which are kept under
version control. That way we can track changes better.

We also have SQL text scripts which populate the database with test data.
That way we can start with a predictable setup when testing.