1)
Why are they called "Rochelayich"?
1.
Malbim: They take Tarshish's merchandise to sell to others
2)
What merchandise is "b'Nefesh Adam"?
1.
Rashi: They are male and female slaves.
3)
Why did these places bring slaves and copper Kelim?
1.
Radak: Each place brought based on what was abundant there.
2.
Malbim: They were security and collateral for the merchandise [of Tarshish] that they took to sell.