A scientist can get emotional too; certainly can an artist. The test is whether the argumentation is lacking and the content of the speech is directed at the listener’s negative emotion. Not whether the speaker gets emotional in the process or delivery.
You have established your argument on several points, including:
1) that the effect of blasphemy on the believer counts as harm
2) that such harm is settled in courts and results in removal of protection from speech
I offer a third point which demonstrates Voltaire and Dawkins must, according to your standard, lose protection of their speech:
3) to deny God’s existence is necessarily blasphemy if God in fact exists (and to the believer, he does).