"Can I count on anyone's help, or am I on my own? Do you have any ideas about where to look for these works of art? How does the thief know how many attempts have been made? Can I consult with you about my assumptions before I start searching? Has the police started investigating this case yet? And wouldn't it be easier to identify and punish this scoundrel? I have more experience in this kind of work, especially in the second part of it."
These riddles are really tough. There are more potential locations than available attempts.
"Where swords are forged and the old gives way to the new" - I think it's Impeccable. Swords were forged there (although I don't really like the phrasing in the present tense), and now it's a pawnshop (i.e., the old has been replaced by the new). "Limoss Steel" and "Impeccable" have equal chances.
"Where seductive demons roar with their power" - Ethereal Reactors, or Reimport.
"Where the great master lives" - either the Capital Prince's Estate (most likely), or the unofficial leader of the Taehan Quarter. Also, any other resident of that area, but that would be too much of a troll.
"Where the small world ends and souls rest" - the Ikigai Gardens, or Aquilon (where you forget all worldly worries and relax), I didn't consider locations outside of Reim.

