I don’t think software is speech, but to play devil’s advocate for a moment; if money is speech then why can’t software be speech? Both propositions seems equally ridiculous, but the Supreme Court has affirmed that money is speech.
Sure. There are also many cases where any kind of speech can be illegal, depending on the context and content of the speech. That does not mean that form of speech is not constitutionally protected.
Legally, whether photographs are speech seems to come down to whether they are taken with communicative intent or not.
This is within the well known (and tested) limits of freedom of speech... which neither TikTok or WeChat software were found guilty of (with or without due process).