I had intended to activate touch tabs unfortunately the Memrise system divides the sentence into individual kana and kanji. If you look at the first 20 sentences, I had added spaces so you'd get something like: "あの" "家には" "時計が" "八つ" "あります" and put those together into the proper order. However, that did not happen so I deactivated it. If you know a way to allow this to happen I'll activate it again.
As for typing out the sentence, I don't think that's necessary. These are meant to help teach one specific word. Even the above if it had worked would be too much since these are for vocabulary and you should not be missing things due to other parts of the sentence messing you up. However, it will be good for the grammar course I'll be adding (a mix of Tae Kim and A Dictionary of Basic Japanese Grammar).
However, there's nothing wrong with having a notepad and writing out the sentence once when you learn it. Or in your case typing out the sentence on a Word document when you learn it and when you get it wrong. It would be great typing practice and a visual reminder of how much you learned/practiced.