I wouldn't argue that they have less First Amendment protections because, as previously described, everybody within the US has the same First Amendment protections. I think that phrasing is both misleading and dangerous.
You're just describing crimes and specific consequences of those crimes that would apply to people in certain circumstances (being a visa holder means you can be deported). Criticizing, for example, the President of United States or holding a particular political viewpoint is (currently) not a crime regardless of your citizenship, residency, or visa status.
As for the border, you can be denied entry for any reason at the whim of the border agent so none of this applies to that at all.
No, these are not crimes for all. As a citizen I am free to associate with communist parties. There’s a Communist Party USA that was a top sponsor for the most recent no kings rally. As a noncitizen I may face consequences for such associations.
It's not a crime if you are not a citizen either. If someone is denied a visa renewal, for example, just administrative -- that's not a criminal proceeding. At no point does anyone have less First Amendment protections under the law.
As for non-citizens lawfully present in the U.S., they have more First Amendment protections than those seeking entry, but still less than citizens.
All this can get visa holders deported:
1. Material support for terrorist organizations (even verbal/written advocacy.
2. Speech deemed to violate the terms of their specific visa category.
3. False statements to immigration officials.
4. (Most obviously) Criminal convictions stemming from speech acts (fraud, threats, etc.)