Excellent questions to ask yourself when making a system of magic in your world. I personally like making it at least visually impressive as otherwise I don't think it's very magical. <<that sounds good
We Hufflepuffs haven't had an intruder in our common room for years! And if some one outside the house were to try to get in, they would simply be covered in apple cider vinegar. Hufflepuffs you know exactly what I mean.