To your first question :
Deadbeat Dungeon does the trick

Second
The merchant sells furniture recipes

Huh oO

Go check in Yuidora in the alleys and such there has gotta be an event that unlocks the deadbeat dungeon

i cant find that place, can you do me a little walktrought ? xD
or a cap from that place

That's the deadbeat dungeon. You get it in chapter 2-3 by doing an event in Yuidora where 2 alchemists talk and one has "deadbeat" over his head.
Its an easy place to get lvs.

For the quest. Can't really remember but, if you can make fish bracelet equip it to Yuela and have her fight that monster. Also use earth bows to snipe his from distance. With Serawi and Crayl.

Well the easiest way to do it is to use Emelita's AoE attacks:
Use AoE attack.
Go to feather to recharge SP.
Skip turns.
Repeat.

Oh,i am in chapter 4 ,and i only have this places...

so i cant discover that place ? :b
Maybe do again the game

Emelitia is low level but i will try it tomorrow ,now i am go to sleep

Looking at your posted character pictures it seems like the equipment you have is what they started with.

If you go Home and click Workshop, Alchemy you can make new equipment.
Equipment requires resources that you get from Excavation and Harvest points on the maps.
Considering you're Craftsman and Synthesis Rank D you should be able to use better stuff than what you have.
Weapon types are specific to the characters (eg. Wil - Hammer, Yuela - Sword), some also give you extra skills.
Accessories such as Shields and rings can be used by all characters.

And what cloth is the best for the characters...?
i thinks is default but i need your think

For you 1st play though get:
Yuela with upgraded Beast Master Armor, dodge path (when you got +1 hit or +1 dodge, click that square and make sure the dodge is activated), together with Ninja Blade and Angel Shield and a +dodge stone Yuela gets to ~80dodge. Also upgrade Flare Hunter Armor for Prevail III.
For Emelita is Pumpkin Robe. It gives Prevail III, Sould Shield III and Aftershock. I was wearing this since I didn't upgrade another one.
For Serawi, Ifrit Tunic, gives a range 9 move and a couple of AoE attacks(Enhanced Battery, Enhanced Barrage also good). As for wearing, I went with an ungraded Harmonic Tunic (good defense + fly skill).

As for NG+
Yuela, God Slayer Armor.
Little Devil Robe for Emelita.
Elf Princess Tunic for Serawi.
The ghotic clothes also give useful skills. Like double action, sonic scream, etc.

Ok very thanks ,but i cant sinth none of that clothes yet xD
another question,where i can find Fish Scale ,because i want to do fish bracelet to get in water with yuela & melodiana :3

You should be able to synth some clothes by now.

Yuela: Beast Master Armor (Ch1+, Aht Lv6), Dark Knight Armor (Ch3+, Sharty Lv12), Flare Hunter Armor (Ch4+, Clear Quest 59)
Emilita: Swan Robe (Ch1+, Suina Lv7), Sage Robe (Ch3+, Melodiana joined)
Serawi: Sprite Tunic (Ch2+, Crayl joined), Undine Tunic (Ch3+, Suina Lv 15, Quest 5 cleared)


Fish Scale
Guard of the Depths (Yuma Lake), Mitorunt (Lake Shisetika, Yuma Lake, + some you don't have)
Not sure that you're high enough level to have the dungeons they're in though.