Yes, he means God is loving. Why say "God is love"? and not just say "God is loving"? John writes "God is love", to emphasis how loving God is, because God is good all the time. God is not good sometimes and evil other times, He is good and loving all the time, and He cannot change His nature just as a man cannot change his race. Love is such a fundamental part of His Person, that "God IS love". If I am a white person, I might say "I am white", I would not say "I have whiteness". Being white is such a fundamental part of who I am, that "I am white", not " I have whiteness".
About God is light:
This is the message we have heard from him and declare to you: God is light; in him there is no darkness at all.
Again, God IS light. By the way, these "God is ... etc" things are predicative, not metaphoric. Light is such a fundamental part of God's person, that it cannot be distinguished from God Himself. If the Scripture said "God has light", this might mean that God has some light and He also has some darkness, but God has only light and no darkness at all, therefore "God IS light". Again, it doesn't mean that "light is God" because there are many sources of light - the Sun, electricity, fire etc, and these things are not God. God dwells in unapproachable light (),
Love is the nature of God's person, and light is God's manifestation (). If we were to go to Heaven and actually see God, would would not see his love, we would see His light, his unapproachable light (). But behind and in His light, in his person, is his nature of love. And producing both His love and His light, is His life, which is the very essence of His person as the Spirit of life. When God's light shines upon us, it becomes truth. If you believe that Jesus is your Lord and Savior, you believe this because God's light has shone upon you and has become the truth. If you have experienced God's grace (unmerited, undeserved favor) it because you have experienced God's love and God loves you. Love results in God's grace, and light results in God's truth. Both love and light result from God's life (), which is the Holy Spirit ().