I respect you for admitting that the law favors just one religion. However, you fail to admit the right of non-believers to promulgate their ideas. As a non-believer convincing the believers that the people they follow are deeply flawed is an important tool. They might not agree with me but I should have the right to preach my ideas just like they have the right to preach their. The only speech that should be banned is where someone calls for death of someone (preachers do it all the time) or calls for any other harm to someone else. You saying something inflammatory about my momma isn’t excuse for me to get violent. It would be nice if you didn’t do that but you have the right to use your words. Slander is different though. I guess the prophets or companions (if they’re still alive) can sure me for slander if I make a false statement about them.
All that said, I’m not stupid. I understand that abolishing blasphemy laws will not put an end incidents where people kill because of their religion. Killers of Salman Taseer and Mashal Khan don’t care about the law. Educating people, teaching them to think critically and being tolerant of other people and their ideas is the only way to mend that.