1. Sometimes you see on tv/films, jokes are made mocking aspects of Islam or Prophet's of Islam such as Isa (this is common in the west). If someone laughs at these jokes, even without wanting to, does this mean he has committed kufr?
2. I saw a video of dawat e islami where he was warning of statements of kufr, etc. Then he taught everyone to pray 'if i have ever committed kufr, please forgive me Ya Allah'. Does this not count as doubting your own imaan, which is kufr itself?
3. Under what circumstances is doubting your own imaan kufr? I mean, what if you fear nifaaq or fear that you may have committed kufr but are unaware of it, etc? Does this fear itself count as doubt (of your own imaan)?