Dont make two characters. You should concentrate on one main character, then once you get him to level 5x+ and grinding is too tedious you can make a second character.
For your builds, they seem good enough to me. Full STR fire/light blade and full STR fire/light blade are good STR builds. As for INT I would say that a pure INT fire/light nuker is the best (Most damage and fastest leveler after level 30).
Pure means that you take all of your stat points and put them either into STR or INT. Str increases your hp and phy damage while INT increases your mana and magical damage. A hybrid is where you put 2:1 stat points ie. 2STR:1INT.
for ur first character, bow/ice is popular for slowing/stopping the enemy before they get to you. If it was bow/fire, u can do massive damage to the enemy before they get to you and you take less dmg. Full int is very dangerous. u dont have alot of health so u hav to do as much damage as you can. Theif is fine, though ive nver seen one.
for ur second character, you can level very fast. perfect character except for job. instead of trader, be a hunter. they are very strong and are damage dealing, like this character.