It's simple, really. I'd like to be aware when my skill level increases (as in, reached 100%, therefore increased in rank). I think giving the player that kind of information is a good idea, since it serves as a notification. I'm often waiting for the moment when something levels up, and i'm not getting that feedback right now unless i repeatedly check the character screen. It's also just nice to see those little accomplishments once in a while, and it would give the player more of an idea about what increases their skills, and how quickly. Enabling this for your officers would also be nice, since it just makes the game a bit more immersive; there's always a bit of empathy when one of your officers levels up his skills.
I do understand that displaying the individual % rewards was removed for a reason though. Seabattles got very spammy, though it never bothered me much. It was a good way of seeing which way you could increase a certain skill fastest, which is now a bit lacking, unless you keep track of all the percentages yourself. I'd suggest a compromise, but i can't think of one, other than displaying what i suggested above.
I do understand that displaying the individual % rewards was removed for a reason though. Seabattles got very spammy, though it never bothered me much. It was a good way of seeing which way you could increase a certain skill fastest, which is now a bit lacking, unless you keep track of all the percentages yourself. I'd suggest a compromise, but i can't think of one, other than displaying what i suggested above.