Cannot open or import a project from MS Project

There should be a provision to open a mpp file, or import all data from it, at least to re-create the WBS.
This will take care of the hardest labor, and the rest can be done manually.

But the currently available import templates are not compatible with MS Project.
As a result, we have to create the entire project by hand: Only the task list is possible to import.

Out of the long list of import templates, the "Activities" template comes closest to MS Project.
Yet the following important things cannot be imported:

1. Task level (1-10)
2. Predecessor task
3. Successor task
4. Dependency type (FS, FF,...)
5. Resources and the efforts by each resource.

I am aware that the prime reason for this "deficiency" is that this type of import requires joining of tables to take care of one-to-many relationship.
On the other hand, the import is designed for simple table only.

For example, a task can have multiple predecessors, and/or multiple successors, and/or multiple resources.
A simple table cannot handle this.

But if we change the rules, it might be possible.
For example, if the multiple factors are handled by a delimiter other than a comma, such as a hyphen, etc.