I've been sporadically active in various political causes over the years. A common theme of many of the causes I've supported (e.g. GLBT rights and feminism) has been opposition to the religious right wing.
More generally, a common theme for me has been opposition to various kinds of religion-based bigotry. By "religion-based bigotry," I mean both bigotry against people because of their religion, or lack thereof, and bigotry rooted in or excused by religion, e.g. bigotry against gays.
9/11 is relevant to religion-based bigotry on several fronts, including: (1) The events of 9/11 unleashed a wave of bigotry and civil rights violations against Muslims. (2) Anti-Muslim bigotry probably had something to do with the American public's tolerance for the Bush administration's war crimes. (3) On the other hand, before 9/11, the U.S. government gave quite a bit of support to Islamist regimes and Islamist terrorism, at the expense of more secular regimes in Muslim countries. (And I suspect that at least some folks in the U.S. foreign policy establishment may still see Islamist regimes and Islamist terrorism as a useful tool against Russia and China.) (4) The U.S. government has continued to bury evidence of support for the 9/11 hijackers by people in the governments of Islamist "allies" such as Saudi Arabia and Pakistan.
Alas, there's also an undertone of Christian theocratic religious bigotry in the Alex Jones sector of the 9/11 Truth movement. "Illuminati" claims, which were revived in the 1960's by the John Birch Society, have subsequently been pushed primarily by religious right wing leaders such as Pat Robertson, Tim LaHaye, and John Hagee, and within the Pentecostal and neo-Pentecostal Christian subcultures, the latter of which has strong theocratic leanings. "The Illuminati" are typically seen as an elite cabal of evil atheists and/or evil "Satanists"/Pagans/occultists, and they are alleged to use progressive political movements, such as feminism and gay rights, as a tool to destroy America and enslave the world -- in much the same way that, in The Protocols of the Elders of Zion, the evil Jewish cabal was alleged to use pro-democracy movements as a tool to destroy (czarist) Russia and enslave the world.
I now think of myself primarily as an activist against religion-based bigotry. In the context of 9/11 activism, I can oppose religion-based bigotry on multiple fronts.
Thus my larger-than-just-9/11 agenda is a bit different from TruthMove's. But I do see TruthMove as having important larger goals too. I see my own goals as complementing TruthMove's. At the very least, it's good to see a left-leaning group like TruthMove, as a counterweight to the Alex Jones sector of the 9/11 Truth movement.