BTMJ, your argument is spot-on. Your books amendment does not protect Dr. Seuss or 50 Shades of Gray while allowing the ban of all political books not approved by the government.
The militia clause of the 2nd Amendment strengthens the amendment by including weapons of war, not just sporting rifles. But there is no requirement that you be identified as a member of the militia to own the guns. One might not actively join the militia until called. When called, they need to have the weapons of war.