[1.] Yes. A criminal acquittal doesn’t preclude a civil lawsuit out of the same claims. First, the acquittal resolves only that guilt couldn’t be proved beyond a reasonable doubt (requiring, say, a >90% confidence level); the standard for civil liability is preponderance of the evidence (which requires just >50%, or perhaps ≥50%, if the injury is easily proved and the burden is then shifted to the defendant to prove self-defense).

Second, liability could be based on a negligence theory; the charges against Rittenhouse were based on the theory that he acted recklessly or intentionally, depending on the charge. Of course, the negligence inquiry made its way into the analysis, because the self-defense claim turned on whether he reasonably feared death or serious bodily injury; that would play a role in any civil claim as well. But at least in principle, there might be more room for claims of unreasonable behavior in a civil negligence lawsuit than in a criminal homicide, attempted homicide, or reckless endangerment case. (One way this could happen is that the standard for criminal negligence in criminal cases is generally higher than for civil negligence, though in this case the jury instructions didn’t seem to reflect that.)