Homosexuality independent researches
First of all even between quotes you shouldn't use heal about homosexuality.
Then you should first try to learn about sexuality. 

what types of homosexuality are there

Homosexuality is a thing, one thing. There is now a loooooot of sexualities, you acknowlodge them or not it's up to you, but there is not such a thing as "types of homosexuality".

how about combination with heterosexuality?

Are you asking about bisexuality ? 

exists some known causes for homosexuality?

Homosexuality is "accepted" as something you're born with. Further than this I don't know any research proving there is a gene or a cause for it to happen.

how about those, who claim, that were "healed from homosexuality?

I guess you should see it as someone who doesn't like some type of food, but buy forcing himself eating some he actully gets over it.
This being said your sexuality is something quite stronger than your food taste, and going against it often comes with depression and other issues.

is some type of homosexuality changeable?

As I said, going against your nature isn't something you should do because it never goes well for you. It always comes with depression, etc...
From your enormous lack of knowledge I guess you're straight, then imagine from now on trying to force yourself to be homosexual ? How hard do you think it would be ? Ho do you think you could deal with it ?