# who were bound by an oath to him

"who had made an oath and were loyal to him" 

# he was the son-in-law of Shekaniah

Tobiah was married to the daughter of Shekaniah. See how you translated "Shekaniah" in Nehemiah 3:29.

# Arah ... Jehohanan

These are the names of men. 

# Meshullam ... Berekiah

These are the names of men. See Nehemiah 3:4.