1)
Why does it say "Lo Hayah Melech Kamohu v'Ahuv lEi'lokav"?
1.
Chomas Anach: He intended l'Shem Shamayim, to clarify sparks of Kedushah amidst the nations [and even so, he sinned]!
2.
Malbim: In spite of his grandeur and his virtue [his wives caused him to sin].
2)
Why did he say "Gam Oso Hecheti'u ha'Nashim ha'Nochriyos"?
1.
Rashi: Even though he was so beloved to Hashem, they made him sin - all the more so, Nochriyos will make you sin, like the coming verse says!
2.
Malbim: The Torah warned not to intermarry with Nochrim "Ki Yasir Es Bincha me'Acharai." They said that they are assured not to veer from Torah via their foreign wives. He told them that also Shlomo thought so!
