>>280657918The real reason is that Q'ten lo only ever does trade with Siltvelt because of stuff with the Ancient Heavenly Empress of Q'ten lo and the Shield hero of the far past. If naofumi wants to get to infiltrate Q'ten lo, they MUST pass through Siltvelt first.
>>280657577It's quite complicated. In the novels, Raph-chan was created as a Shikigami, then became a Familiar the moment they gone back to Raphtalia's world(with the appropriate shield being unlocked upon entry). Then Naofumi modified some of Raph-chan's settings(Raising her mutation a bit, not to the point she becomes uncontrollable) so she could have growth, in the sense of being able to level up and stuff.
Also the soul of rifana inhabits Raph-chan, her bangs resembles that of rifana if you look closely. This is the reason Raph-chan had an ego and formed so quickly, since rifana followed Raphtalia ever since she died.