Classic English language comedy scenario:
Question: "Should I go right or left?"
Answer: "Yes!"
Can this happen in Czech, too?
Yes, but with "nebo". "Anebo" is quite clearly disjunctive. And in written text a comma also denotes a disjunctive or.
Why can't we translate "Mám jít..." by "Do I have to go..."
"Have to" is translated as "muset". "Mít + inf." is translated as "be supposed to", "should",...
Why not "Shall I go …"?
added
I hope I am correct, but if it is connected with "I" or "we", it is a suggestion. But in other cases it would be an order "You shall go to the right."="You must/have to go to the right.".