> What terrorist acts have the Taliban committed?
Giving aid to a terrorist group that commits those acts doesn't make the Taliban less complicit. See this UN report from June about how the Taliban is still closely tied to al Qaeda (https://edition.cnn.com/2021/06/02/middleeast/un-report-tali...). As for what atrocities they've committed, there's a long list on Wikipedia, many of which meet the definition of terrorism (https://en.wikipedia.org/wiki/Taliban#Condemned_practices).
> Why does the U.S. need a foothold in a region on the other side of the world?
So many reasons. First, to contain China, which is the principal threat to America's prosperity and control in the future. Second, to support other democratic nations like India, who will suffer from the Taliban's resurgence. Third, to expand our economic interests. Fourth, to continue our mission to sustain human rights which the Taliban is already eroding. There are others, and I am certainly not a foreign policy expert, but my point is - there's something there.