They are welcome to continue operating as long as they are not owned by a Chinese company

Yes, according to the recently passed law. And the justification for that law is the notion of "enemy of the state," which is, IMO, a tricky argument to make when they're such a huge trading partner. It makes a lot of sense for something like N. Korea, Iran, or Russia where we have pretty much no economic involvement, but China is a weird one because of our close trading relationship.

To me, this smells like the US doesn't feel comfortable not controlling every massive SM company. Would we try something similar if it came from a non-enemy, non-ally like India? That I even feel unsure of the answer is a massive problem IMO.

manipulation of that data

Which is speech. If I (US citizen) built something like TikTok and manipulated the sorting algorithm to show content consistent with my political views in an effort to change the outcome of the election, would I be shut down? Surely I have some cover from the 1A. Facebook, Google, and Twitter seemed to get away with some of that, and X seems to be getting away with it now. If TikTok was owned by a US company and manipulated data in exactly the same way, would they be okay?

This smells like they're arguing the 1A only applies to US-based companies. It should apply to any company doing business in the US for customers who are in the US.

China having access to the data is certainly problematic, but does is it actually something that rises to the status of a national security issue? I completely agree with banning it for any US government personnel (esp. those who work at secure facilities), and I'm fine with an active campaign against people using it, but I think banning it outright unless China's involvement is eliminated oversteps the bounds of the Constitution. I should be able to use any app I want and companies should be able to distribute any app they want, but if an app is used to commit a crime, that crime should be prosecuted. If certain apps are more likely to be used for crime, they should be closely monitored by law enforcement. But distributing software, by itself, should never be a crime outside of things like IP law.

It’s on-par with Russian election interference, although perhaps a little longer lasting and more subtly done.

The Russian election interference concern is overblown IMO. Yes, they have a heavy pro-Russia information campaign where they want US citizens to elect pro-Russian representatives. Pretty much everyone does this, and IMO it's not election interference unless there's actual fraud (i.e. ballot box stuffing, manipulation of voting machines, intimidation, etc), none of which there's any evidence for given Trump's fruitless lawsuits in the 2020 election. It's a bunch of FUD IMO.

Yes, Russia and China suck for trying to sway American votes, but at the end of the day, Americans are the ones deciding the outcome of the election, not Russia or China, and it's the US government's job to counter that misinformation, but not by banning misinformation sources, but by pointing out and challenging the misinformation.

In the US, we do things differently. Instead of banning things we don't like, we challenge and inform so the general public can make a better decision. Or at least that's how it should be. The moment we collectively decide to let the government think for us is the moment we set ourselves up for fascism, and I want no part in it.