Projects Migration from 7.0 to 7.1

Hello Experts,

We are migrating all projects from SolMan 7.0 to 7.1 and need some input from experts...

1) Which transaction is better to use from Migration SOLAR_MIGRATION or SOLAR_PROJECT_ADMIN, i want to migrate multiple project with each and every project structure and all documents within all tabs of particular project.

2) Which transaction has feature to transport multiple project in single TR

4) Is Transport Reqest the only option for migration???

Waiting for your valuable inputs....

Thanks,

Prarthan