What's the insult then? That she wasn't perpetually a virgin?
Protestants have plenty of respect for Mary. Saying that she wasn't perpetually virgin is NOT a sign of disrespect.
The prophecy was that a virgin shall conceive and bear a son. End of story.
Whatever happened after that, whatever she did after that, is of no consequence to anybody. It has no impact on Jesus work of redemption. It is irrelevant to anybody's salvation, justification, sanctification, whatever....
She was just a normal, sinful human being who God used in an extra ordinary way, like He used so many others.
Yes they do, but then again your fringe views on the subject are not representative of the vast majority of Protestant views.
That’s the simple truth. Mary’s destiny was great but not good enough for the RCC.