Do SEVERE chronicMigraines (& I mean feeling carotid and head blood flow start to SURGE while constricting,)cause significant damage to blood vessels?

Thankfully no. Migraine headaches make you hypersensitive to sounds and every sensations. Every indication is that sounds and sensation are normal events that you are hypersensitive to.
We don't know! What a great question. The truth is we don't really know. There is a suggestion in the literature that chronic migraines may (MAY) be linked to a slightly increased risk of stroke, potentially because of mild long-term damage to blood vessels. But research is ongoing into this question. The best thing to do is to treat the migraines and make sure your blood pressure is under good control.