The white horse I think symbolizes Antichrist and it’s attending man centered philosophies(or the various social type “isms”), such as progressive socialism and hedonistic Utopianism, that seek to peal men away from God to serve a man centered state....which in turn leads to war, famine and pestilence. When people are stripped of their basic moral moorings, societies eventually become tyrannical, then implode in their inability to negotiate the fiscal, legal, and security demands placed upon that society. External enemies may view such societies as ripe for the picking...such as how Islamic Jihadis may view western nations at this time. The white horse symbolizes the attempt to forcibly build a “new world government” by force and by the use of a syncretized civil religion with Satan at the back of it all.
Civil wars result, famine and disease become rampant as persons of competence who could ameliorate the conditions are killed off by the political agencies of the dying regimes, by disease or strife, or they have gone into hiding and are missing. The 4 horsemen depict a dark vision of the future of humans being brought to the very end of ourselves and our vain attempts to make ourselves into “gods”. Only by Christ intervening will save what ever life is left upon the Earth at that time.
“The white horse I think symbolizes Antichrist...”
I looked, and behold, a white horse, and he who sat on it had a bow; and a crown was given to him, and he went out conquering and to conquer. Revelation 6:2 (NASB)
The Greek word for “crown” in this verse is “stephanos”. It is used 13 other times in the New Testament, and ALWAYS in relation either to Christ, His apostles, or believers in the church. It is NEVER used in describing “anti-Christ.”
A good argument can be made for this view, and you have laid out the foundations of this argument. I think the argument that the White Horse is Christ or Christ's gospel going out into the land to be followed by war, famine and pestilence is also a good argument. Both can be supported by both NT and OT scripture. Personally, I can't make a stand on this issue because I am just not sure - I don't feel the Holy Spirit leading me one way or the other. Perhaps these parts of the scripture are meant for later generations and will become more obvious as more historic revelation occurs.