For your first
He does remember, he's just pretending not to at the start. Likely so it doesn't come out at some point that he's not even from that Shard... and the whole Source and Reflections thing in the first place.


The second that's explained by completing the Crystal Tower raid story
In short, he already had the Allagan Eye which came with the "blood of Allag", and only one with it could operate the Tower. Doga and Unei give theirs to G'raha Tia, giving him the second Allagan Eye.