#2 That one is super easy. You take vanilla icecream and let it go a little soft. You sift in your favorite matcha after taste, stir it in and freeze it again.
I normally make it quite strong but keep some icecream just vanilla and serve it with oat cookies. The crunchieness of the oat cookies, the sweetnes of the vanilla and the taste of the amtcha goes well together.
You can make if from scratch but I have never tried that