Please don't mistake this question for In-universe speculation vs. original research
I have answered two questions in past few days and both my answers made me wonder about this. What if person asks question about fictional universe like Harry Potter, Star Wars or Tolkienverse and answer does not lay in that particular universe? For example someone asks if guns would be any good in Harry Potter. Now, truth is that there are no guns in HP because it is books for kids. There are some story measures that explain lack of regular guns, but one can deduce by simple logic (provided that he/she has good knowledge of the universe), that guns would in fact be very effective. What is right answer? Cite story measures that explain lack of guns? Say it is book for kids, which is answer outside of that particular universe? Or explain why guns would be very effective, but just aren't there, even if that means to speculate a bit but very "safely"?
And what about sci-fi? What if there is very basic explanation of some phenomenon in the original work, but person providing the answer can very simply ratiocinate more elaborate and science friendly answer, that would not in any way disrupt the universe and would be in fact just more elaborate version of simple answer provided by canon? Is such answer right and legit?