No Restoring backup will not of impact on device operationYes it dosen't matter you can retore backup prior enabling High availabilty or after enabling High availabilty  

This is probably due to permission issue . the user which you were trying to configure didn't have privilege to write anything the user only had read access. To resolve this we need to allow user with READ , Write permission so the DNAC can use that ...

No we should take backup locally the spaces allocated to DNAC is for internal purpose only and hence we should not take backup locally  

NO as of now this feature is not there  

We just need follwoing thing to keep in mind while restoring the backup :1. Make sure the backup that you want to retsore has same version from where backup is taken 2. Ensure all aapplication version are same IF you above two parameter match then yo...