1. It feels like you're trying to walk me into some imagined rhetorical trap; if that's the case, feel free to speed up.

2. It's completely possible that justified violence could happen in the US; it would, as anywhere, depend on what violence by who for what reason, but there's nothing that makes the US special in this regard. In the past, on multiple occasions (resistance to slavery, for example), political violence in the cause of freedom has occurred, and I don't think that was immoral.