I think it depends on what you want to get out of this game. Just clearing the game, then experiment and have fun. If you want to go up against the post-game content then maybe a little more focus will do by looking at skill guides.
I'm going to assume you want to stand a good chance in the post-game content. So I'd recommend getting abilities that will help with Metal Slime hunting, too, for quicker level gain and therefore quicker skill point gain.
For Hero, I think your'e fine with your set up. If you want Gigagash then put all points into Swords to 100 and Courage to 100 to get the ultimate ability. However, if you don't care, then I'd say focus more on Spears first since it's a powerful weapon throughout the game. It's only at the post-game where you realize that Swords really shines.
For Yangus, I say just put all points into Axes until Executioner since it's a powerful attack that also doubles as a Metal Slime killing technique. I personally don't find any of his other weapons and abilities that useful, so I put them all into Humanity afterwards. Maybe some other skills here and there for fun. But basically Axes then Humanity.
For Jessica, I'm doing Staff until like 57 first to get Caduceus for free healing, then more into Staff for more MP and MP Recharge since she's my main offensive magic user. Then I put some points into Sex Appeal since the later abilities are great. For weapons...I don't know how bad Whips are now and I'm still going through the game, however, I think Whips is still pretty good. Knives I never liked as much, but if the changes from a few pages back are true, then perhaps knives are the way to go this time for maximum offense. I still magic is the way to go for her though.
For Angelo, if you want quicker offense from him, I'd recommend Swords instead of Bows. But Staff is great for him as well since he's my main healer for most of the game. Charm, I only put into like 13 points just to get that Snicker/Grin thing, which helps in some battles randomly at times. Otherwise, I put it all into my main weapon of choice. I usually go Swords or Bow for him. If I'm more serious about post-game stuff, I go Swords. If I want to mess around, I go Bows. With that said his ultimate bow, when used in battle as an item gives free healing, so regardless of whether I make him go swords or bows, I always put that bow in his inventory to use in battle.
