Was Malkas Sheva a queen?
Refer to Melachim I, 10:1:1:1,2 and the note there.
What did she want to test?
'Rashi': Whether what she heard about his Chachmah is true.
What are "Chidos"?
'Rashi' (1,2): They are riddles, like "Achuda Na Lachem Chidah" of Shimshon (Shoftim 14:12). Some of these riddles are in Targum Sheni of Megilas Esther 1 . Malbim (Melachim I, 10:1) - human Chachmah cannot know all riddles. Sometimes the matter is hidden, e.g. Shimshon's riddle. Who would 'prophesize' that he killed a lion, and bees nested in the carcass and made honey?!
Radak (Melachim I, 10:1): It is matters hidden with Chachmah. She was a Chachamah.
Four are brought in Midrash Mishlei 1:1 and Yalkut Shimoni Divrei ha'Yamim II, 1085. (PF)
Why did she come with a great legion?
Refer to Melachim I, 10:2:1:1.
