What are the different types of ghusls one needs to do? I am a bit worried sometimes that there might possibly have missed a ghusl that I was meant to do? I only know of the one after hayd, junub, nifaz.

I touched a dead body when I was younger but it was after the body had received the 3 ghusls so I'm assuming that there is no ghusl required for me now.

When I was a bit younger I said a word of kufr in a moment of anger and ignorance. I have repented to Allah for this deeply back then and now as well. Is there anything I need to do like a ghusl for that in this case? Does one need to do a ghusl if repenting from shirk? (not that I have ever said a word of shirk I hope insha Allah but just asking).

I committed many sins in my lifetime (which you probably gathered by my many posts) but I am trying to make up for it now. However, I never once beleived there was a god other than Allah or doubted in Allah or prayed to any other god. When I was younger though, as part of the school I used to go to the church with others and sing the songs with them before I knew singing was haram (and probably the whole thing was haram). I never meant it as a way of worship though and quite often I would say the Shahaadat while in there with the school. Do I need to perform a ghusl? :S