No. Paratext 8 and Paratext 9 share the same data structure, so projects won’t require migration from Paratext 8 to Paratext 9. Members working on a shared project can use Paratext 8 or Paratext 9 and share changes with each other.
The person migrating the project will need to use Paratext 8 to migrate it. Paratext 9 does not have the ability to migrate Paratext 7 projects. But once the project is migrated, everyone on the team can work in the project in Paratext 9. There is no need to migrate a project from Paratext 8 to 9, migration is only needed when going from Paratext 7 to 8 or 9.
There is no impending deadline to upgrade to Paratext 9. Since both versions work on the same data, some of your team may want to wait to upgrade. We would encourage those who can to upgrade as soon as possible. Then you will be able to help others learn the new interface when they upgrade later.
No. You can download and install Paratext at any time, but you must register in order to use it. Registration is free to everyone.