I'm learning German at a fairly low level so I ask this from the perspective of wanting to learn, not as a challenge.
Wouldn't "have to" be "müssen"? In what cases would you use "sollen" to have a similar meaning?
And "sollten" is either Präteritum or Konjunctive II, which as I understand it would both mean "should have", though in different senses. Why is that a more proper translation of "should"?