JOEL - It probably is impossible for anyone to think that any good Christian could love Satan; but as you point out we have been told to love everyone, including our enemies(Matt 5:44), Satan being the worst enemy of all.
When Christ spoke these words his purpose was to help mortals living on this earth to be able to get a long with other mortals. This was the main purpose for many of his teachings. He hardly intended it to be applied to Satan and his fallen angels. And I don't think it is necessary for us to profess any love for Satan as a requirement for entrance into heaven. However those scriptures you quote(Psalms 97:10, Amos 5:15) only tell us that we should hate evil. There are many mortals on this earth who could be labeled as evil, but we are told that we should hate the sin and love the sinner. So is it possible for us to hate the evil that Satan does but love him because he once was our spiritual brother? According to LDS doctrine Jesus, Satan and all of God's spirit children were brothers and sisters in the pre-earth life. It seems logical to believe that Heavenly Father loved all His spirit children even the one who would eventually become Satan. According to Joseph F. Smith:
"Naturally, the expression that our Eternal Father loves Satan needs some qualification. There is no doubt that there was a deep sorrow and weeping when Lucifer rebelled. From all that we have received pertaining to the pre-existence, we learn that there was a time when Lucifer held great authority and was known as the light bearer. No doubt at that time he was well received and greatly honored. His great sin lay in the fact that he rebelled against giving to every soul the great gift of free agency. Naturally, there was weeping in heaven when the rebellion of Lucifer was introduced, and our Eternal Father wept, just as a mortal father who loves righteousness would weep over a rebellious son."
I think rather than worring about who we should and should not love, we should just keep the spirit of love within our hearts at all times for everyone at the same time avoiding all forms of evil.