The character is first level, so the answer is first level to both questions.
The RLO basically sets the amount of XP needed for the next level to be the number given for the character's level plus the RLO. It has no effect on any other level based criteria.
So a first level Fire Giant (who has 110,000 xp) needs 130,000 xp to get to second level.
As for casting level and other level-based criteria, his actual level is what is used.