Hey JobClass,
I'm glad we can help. Skills in this game are
extremely important! To the point that I recommend you use everyone's skills until their SP runs out, and then swap them for another member until their SP runs out (or you can buy Energy Drinks, Potions, etc in town and refill their SP if you want.) As you've probably noticed, skills level up the more you use them - late in the game, you will NEED certain skills to be at their maximum level (level 8 ).
Also, late in the game, accessories will be vital to your success. They will literal make the difference between victory and certain, horrible death.

I don't remember the names off the top of my head, but in the late boss battles, you'll want to equip accessories that block status effects, like flinching, sleep, confusion, poison, etc. Otherwise the bosses will just destroy you and you will hate Kemco forever!
For gathering materials, there's a couple options:
A bit further into the game, you'll be able to get a character named Penta, who will collect materials for you in one dungeon while you're off exploring another (he doesn't always get a lot, but hey, anything is better than nothing.) In the IAP shop you can buy Penta's Helpers (up to 3) to increase the amount of materials they collect.
Also in the IAP shop you can buy a boost function to turn off encounters (as well as boosts for 2x gold, experience, skill growth...) You
can pay real money for the IAP,
but you can also earn it through random encounters - although I don't think you earn enough from one play-through to unlock all of the things I've mentioned above.
I spent about $5 US on IAP for this game, because I really love Kemco's games and don't mind giving them a little extra now and then, especially considering their games aren't that expensive to start with. But, I would never recommend paying for IAP, because a lot of people don't like it no matter who the company is, and don't want anything to do with it. So, the option is there - you can buy IAP, or earn it through random encounters. Totally up to you.
P.S. Just a heads up, a lot of the features in this game are not typical of Kemco's other titles. They're all RPGs, and (almost all of them) are fun, but there's only a few titles that have the material collecting, weapon crafting aspect - and overall I think Justice Chronicles is the best out of those few.
But a lot of their other titles, the gameplay is totally different. Justice Chronicles is in my opinion among the harder, and more "sophisticated," games Kemco has ever released. (Also one of the longest - I've played over 60 hours and still have not finished all the bonus content.) I love almost every Kemco game, and I think you chose a great one to start with, but I'd hate for you to think all their games are like this one and then get burned on your next buy.