Can validators be swapped?

Yes, if the delegation has not been accepted yet. If delegation is still not accepted the token holder can cancel and request a new one.
But if the delegation has been accepted and/or started, the delegator has to first do an undelegation request then once the next epoch starts, make a delegation request to another validator for the next epoch. So 1 month they won’t be able to stake if they want to change a validator unfortunately. This will be changed in the future, but we are launching with this process.