If you are interested in entering sparring events, I feel you must not only understand the rules, but the philosophical and technical underpinnings to them.
I am speaking in generalizations here, and am certainly not trying to say "this is better than that" in this post, so please keep that in mind.
In order to get awarded a point in a traditional karate tournament, your technique must look like it would be able to incapacite your opponent if you did not pull it. Therefore, balance, a solid foundation, and kime are all required of your technique (and ideally, zanshin as well). If you are off balance but land a punch, the point will not be awarded. Another example - jumping backfists will not be awarded a point.
Also, the definitions of focus on kicks come into play. I could be wrong, but I believe in open tournaments if you sweep by someone's face with a hook kick, and his block isn't there, you would get a point. In many traditional tourney's, you would need to stop your HEEL a fraction of an inch from your opponent's face, then put it down - no "swinging through." To do otherwise will be interpreted as your distance being wrong.
I have seen people become upset when they think they score but are not awarded the point. A thorough understanding of the rules would eliminate that.
I hope there is something helpful for you in this post.