The only thing I wanted to respond to was your comment about meeting more Christians. I was in a youth group all throughout middle school and high school. Went on 3 Christian retreats, taught vacation Bible school in the summers, and volunteered at a Christian led soup kitchen. My wife, parents and half my friends including my best man are all devout Christians. So, no I think I know plenty of Christians. Neither my 2 pastor's, nor my youth group leader, nor anyone that I ever talked to ever mentioned that they thought the Earth was only 4000 years old. Now, In my senior year of high school I did attend a bunch of different churches (my parents were trying to find a new one), and I believe a person or 2 talked about a young Earth. Now granted it's not like I go to every Christian I meet and ask them how old the Earth is, but the topic of whether or not to take the story of Adam and Eve literally does come up quite often.
Also, you said that non-young Earth Christians are inconsistent. Inconsistent with what? I'm sure you realize that the Bible contains both documented history and metaphors. Who are you to decide what is story and what is real. You don't have special powers, it is only your belief that the story of Adam and Eve took less than a week. To say that any Christian who doesn't believe the Bible to be exactly how you interpret it is being inconsistent is just comical. In your world it is only black and white. "Christianity is the only true religion, why...because that's what I believe", "Young Earth is the only consistent Christian belief, why....because that's what I believe." My guess is if you were born in Pakistan, you'd be saying, "Islam is the only true religion."