[1] Others executed for criticism ("poetry" about muhammad as it's generally called in the hadith) include "Abu Afak", "Al Nadr ibn al-Harith", "Uqba bin Abu Muayt", "Ka'b ibn al-Ashraf", "Abu Rafi' ibn Abi Al-Huqaiq", "Fartana" and I doubt this is anywhere near the full list.
Note that this was most definitely NOT common practice during those times. You should read some of the texts that survive from Roman fora in the same area. Let me tell you Romans are not afraid -at all- of calling the head of the army a coward, and comparing them to dog entrails (I assume that's not a compliment). Same sort of things are regularly said about the governors and so on. And in at least one instance that did not even lead
Again: There is certainly a lot in the OP's post relevant to HN, but i would submit that sweeping statements on religions are not
And what about all the other ones ? It's not like executing people for criticism is something islam's prophet did once. Well, compared to the thousands of people he ordered executed (e.g. the massacres he ordered around Mecca) it may not be that much.
This is not a sweeping statement about a religion. It is a simple statement of fact. Just because a statement is currently policitally inconvenient or "sweeping" doesn't affect my opinion of it at all. As you very well know, there are far more damning sweeping statements one can make about islam that are equally true.
Frankly, islam was created through a protracted and bloody war. Everyone, including muslims, agree on this. Do you find it all that surprising that atrocities happened on both sides ? The problem I have, of course, is that one side claims to be the definition of good, and went on to commit massacres elsewhere in the world on a scale never seen before.
Why do you feel the need to reject historical fact ?