The controls are pretty barebones tbh. Left Click/Enter/Scroll Down to advance text (scrolling can be too quick that it causes errors sometimes). Right Click/Spacebar *during* conversations to hide the textbox; doesn't seem to work if you aren't mid-convo (like on the Home screen before/after Chats).
There is no quick undo or page-back, as far as I know. If you're unsure, usually the top choice is the "nice" option, though after the fever passes you're in the clear permanently. Just be nice to our dear Sylvie and nobody has to be dissappeared, ya?
I'll be lurking here for a bit again, ask away if you have any more questions.
Edit: Also, in 3.0 the CTRL key works as a safer skip than speed-scrolling the mouse. I don't have my 2.5.2 install at the moment, can't remember if that was a thing then.