Updates are constantly made to the constitution. They're called amendments
Amendments have been added since 1776
Again I'm not sure what you're arguing here... you're asking for things that have already been done.
Regarding domestic terrorism, terrorism is terrorism. And they already have lthat in the oath... "protect America from all enemies foreign and domestic"
They could make stronger laws around domestic terrorism but that wouldn't need a constitutional amendment. Congress would just need to create a federal law around it, which I fully expect to happen.
As far as Trump, the strength or weakness of the constitution isn't what allowed him to do what he did. The constitution has set laws against what he did. He just regularly broke those laws and that's why they're on his bumper right now.
This impeachment trial (no matter how it goes) is just the beginning.
Amendments are certainly made. We know issues of terrorism are not the when speaking on foreign and domestic issues. I separated the constitution and laws needing to be changed. If he constantly broke laws, why isn't he being impeached on those laws he broke?
The US has not fully comprehended domestic terrorism. Constitution needs to be revived because people forget or ignore the government part in the First Amendment. It needs to be dumbed down.
Feds and state need to rework how they approach domestic terrorism. The constitution is another issue that needs to be discussed.