I really don't think claustrophobia is going to be an issue. I don't suffer from it to any severe degree myself but I'm just thinking of queue lines like the old Space Invader 2 and the tunnel bridge of the Black Hole. If you have ever queued from the entrance to SI2, all the way through, you'll know what I'm talking about. It was dark, hot, stuffy, slow, crowded and much narrower that what we are seeing on The Smiler. I would be interested to know how many people actually suffered from panic attacks there, I'd be willing to bet it wasn't many.
As from a fire point of view, again SI2 would have been much more likely to cause panic. H&S were fine with that, as I am sure they are fine with may more enclosed or indoor queue lines.