1)
Having mentioned 'Chasanav', why did the Pasuk add 'Lokchei Benosav'?
1.
Rashi: "Chasanav" refers to his sons-in-law (who lived in Sedom), "Lokchei Benosav", to the Chasanim to whom the two daughters who were still living at home were betrothed. 1
2.
Targum Onkelos and Targum Yonasan: They are in fact, one and the same - 'his sons-in-law who were married to his daughters'. 2
2)
"B'Einei Chasanav" connotes that they could see. The angels blinded everyone!
1.
Moshav Zekenim: They did not really blind everyone. Rather, it was an illusion, so they could not find the house.