This will work, but at some point of time you will need to migrate the VMs from the vDS to the std switches. I would include:
4. Migrate ONLY vmkernel adapters.
5. Remove the host from maintenance mode, migrate VMs back and migrate VM networking from vDS to std switches
6. migrate the second 10Gbit port from the vDS to the std switch
7. Remove host from vDS
You don't need to disconnet/connect the host from vcenter, with this you are good to go.