Short answer... YES. The roof on your coach is designed to be a walkable roof.
Longer answer - IF the roof is "sound"...which depends on the age/upkeep equation, and if NOT damaged. If the TPO/EPDM roof membrane has been kept clean and sealed, and there hasn't been any water intrusion to rot the underlying roof structure - it should be perfectly safe.
If you don't walk on the roof then how can you inspect the dicor for cracks? I would think the Freedom Elite series is no different than any other Thor coach you should be able to walk on the roof. If you have doubts contact Thor or your dealer