The alien space ship ran on psychoenergy computers, so couldn't Ranma have just thought Translate and have the super advanced alien computers work on understanding and outputting japanese?
Ranma’s and Ryoga’s discussion on the moral dilemma of taking another life especially Ryoga using Saffron too argue his point. Killing is the last thing Ranma would want to do but once he decided to do it he was okay with the decision. He was not shown to be tormented in the least bit from killing Saffron, granted Saffron being reborn may have something to do with this but even before he knew that it didn't bother him that much. Ranma would have to be convinced to kill someone but once he makes that decision that would be the end of it.
I also think Ranma sees killing people more as cowardly then justifiably wrong.
Ranma anger at Trencard Cologne ‘s the reason you suck speech to Shampoo. All of Ranma’s life he has heard that very same thing from Genma. So he would instantly know just how much those words hurt Shampoo.
Ranma in the manga is a neat freak, hates a messy room, and will start cleaning a dirty room without thinking about it as shown by his starting to clean Miss Hinako's room and having to think about it to stop. Which is why when he gets his own room away from his father it is always shown to be spartan and relatively tidy.
Ranma’s and Ryoga’s ki blast seem more of a reflection of their defense mechanism then their emotions. Ryoga is more keen to depression at his lot in life. While Ranma’s arrogance is shown more as his unwillingness to appear as less of a man in peoples eyes and casualness when fighting then the braggart he is usually depicted as. There is a reason a spiral of depression and dark thoughts are easier to draw on than confidence.
Exactly Ranma has perfect confidence in himself until it appears that something is wrong with him. Ranma wasn't worried about Principal Kuno showing Ranma's grade to everyone which implies that Ranma does not generally get bad grades or he really doesn't care about them (a view point that is countered by Ranma's actions when Principal Kuno implied they were extremely low). And when when Ranma speculated on what to do about Ukyou and Shampoo he wanted them to stop chasing after him, but didn’t want them to think of him as any less of a
Why was Nabiki disappointed that Ryoga wouldn’t haggle with her, because that is what Ranma always does? Even while in a hurry and being blackmailed by her he'll try to negotiate a lower price.
Its actually makes a lot of sense for kuno to have the greatest psychic strength but the weakest skill. Kuno’s abilities are actually very similar to Kyoya Izayoi from Demon City Hunter. Nenpo is the ability to project Ki by force of will to cause a phenomenal effect in physical reality so that objects that user touches convey the lethal edge of an actual bladed weapon. If kuno uses a similar technique that means that this entire fighting style revolves around psychic projection. Kuno has been training his psi skills all of his life however the moment he received the Hououken he’s been focusing more on his sword skill and physical ability letting his psi skill atrophy while keeping the strength.
