Sister, thank you for adding the awesome questions!
Sheba = "seven" or "an oath"
Dedan = "low country"Lets start with the last one first...
Dedan, we don't seem to get much from the meaning of the name, so lets look at the scriptures.
Jer 49:8 Flee ye, turn back , dwell deep , O inhabitants of Dedan; for I will bring the calamity of Esau upon him, the time [that] I will visit him.
Eze 25:13 Therefore thus saith the Lord GOD; I will also stretch out mine hand upon Edom, and will cut off man and beast from it; and I will make it desolate from Teman; and they of Dedan shall fall by the sword.
Eze 27:15 The men of Dedan [were] thy merchants ; many isles [were] the merchandise of thine hand: they brought thee [for] a present horns of ivory and ebony.
Eze 27:20 Dedan [was] thy merchant in precious clothes for chariots.
Eze 38:13 Sheba, and Dedan, and the merchants of Tarshish, with all the young lions thereof, shall say unto thee, Art thou come to take a spoil? hast thou gathered thy company to take a prey? to carry away silver and gold, to take away cattle and goods, to take a great spoil?
Merchant : 
do I try to buy or sell what the Lord has given...????