I was speaking with a police officer friend, and he pointed out that you don't have to mirandize the suspects for any conviction to stick. You just cannot use any statements they make without first informing him of his rights. So, if he has not been informed of his rights, and blurts out "Yeah I did it. And I'd have gotten away with it if it hadn't been for those pesky kids, and their stupid dog," that statement cannot be used in court to convict him. However information obtained in such a way can be helpful in gaining knowledge of other bombs, or even other terrorists.
It is also not uncommon for investigators, and detectives to read the Miranda warning every time the question the subject. They do this in the event that they gain some glimmer of information that proves the subject's guilt. It's also in the event that the arresting officer did not read the Miranda warning. They also do not have to read it verbatim as you have gotten to know it. If the officer says, "Hey bud, just so you know I HAVE to do this. You know legally you don't have to talk to me without a lawyer present, and if you need one, we can go get one for you. They might use anything you say to me in court," you have been informed of your rights, and therefore Mirandized. They actually got at least one conviction because he thought it had to be read to him exactly like in the TV shows. And he admitted he killed her.
Now, to the meat of the issue. I agree with you that it's dangerous to suspend rights of US citizens on the basis of "terrorism" not so much for this guy, but for the precedent we could be setting ourselves up for. If they can strip the rights of any American citizen on the ACCUSATION of terrorist ties, we have a HUGE problem. I don't mind if there is a hearing to make that determination based on presented evidence, but before the person has had any chance to defend themselves they lose rights? It smacks of a modern day Witch Hunt.
"I would rather be exposed to the inconveniences attending too much liberty than to those attending too small a degree of it." Thomas Jefferson