Answer 1 : Yes it called upcasting but the way you do it is not modern way. Upcasting can be performed implicitly you don't need any conversion. So just writing Employee emp = mgr; is enough for upcasting.
Answer 2 : If you create object of Manager class we can say that manager is an employee. Because class Manager : Employee depicts Is-A relationship between Employee Class and Manager Class. So we can say that every manager is an employee.
But if we create object of Employee class we can not say that this employee is manager because class Employee is a class which is not inheriting any other class. So you can not directly downcast that Employee Class object to Manager Class object.
So answer is, if you want to downcast from Employee Class object to Manager Class object, first you must have object of Manager Class first then you can upcast it and then you can downcast it.