well, because for a lvl 20, there are not many hard quests. Hard quests like Elin gun, Kanako and steamboat design, are all pretty hard for a lvl 30 anyway. So I recommend keep lvling up in North/South island first, until you are lvl 30+.

I found some good armour/weapons for a lvl 30, all DEF+ or ATK+, so best for fire warrior:

Wooden Shoes DEF +14 (Japan 460G)
leather armour DEF +16 (revival Island 560G)
Bronze Halberd ATK +30 (China 510G)
Ninja Helmet ATK:+5 DEF:+10 (Japan 510G)
Iron Cuffs DEF:+16 SPD:-2 (Maya 460G)
Warrior's Falchion ATK +15 DEF +15 (Japan 510G)
Great Sword ATK:+18 DEF:+10 (China 460G)

As you can see, one very good thing is you dont need to compound anything!!! And they are almost the best armour for a lvl 30 anyway!!! You can search on the DB, for rank <15, they have almost the highest DEF/ATK!!! But you just need to do some travelling, which is more reliable than compounding... just make some rafts and boats...

Not sure if I helped, but here you go, hahaha...