The Robe of Knowledge is located in the Summer Shop which is located in Battleon, but only around June/July.
One can find more information about AQworlds by checking the information section of their site. For outside knowledge, their wiki page also contains much invaluable information.
I don't think you can find one in aqworlds.
to find the secret 2 you have to find the ninja spy in tercessuinotlim on aqworlds.
I believe you can find the book "The Robe in any christian book store.
You can find him at the farm.
you can find it in the darkovia
The Marsh
yes! (I find)
i greengard
trainers
in tercessuinotlim
sewer