I have heard many claim that Islam is a religion of peace. If that's true then why are you not free to disbelieve? Supposedly apostasy is punishable by death according to Islam. (I read it in an answer to some other question on this site). That doesn't seem very peaceful to me. If you are brought up Muslim are you not free to change your mind?
Nowhere does the Quran state that an ex Muslim should be put to death. What you are talking about is a Hadith that has many different interpretations and we are not sure if the Hadith is authentic. In fact, if we read in the Quran in Surah 4:89-90, it states that if an ex Muslim reclines to peace, you shall not hurt them. Unlike the bible which clearly states in Deuteronomy 13:6-9 that they shall be put to death.