hey i have 2 doubt about reputation and credits that faction give u , first is only dailys ways for earning reputation or exist another way , and credits can use in all faction ( example) if i have 3000 credits in one faction i can use this 3000 credits in another factions? plx if anyone know tell me =) thx

As far as I know, the dailies are the only way to earn reputation points. Side questing in the zones increases your affinity with each faction which you will need to have access to their merchants.
Go to your Profile -> Reputation tab, that should explain your 2nd question.