I don't know if it is already possible yet* but as the title suggests I think it would be really convenient to have access to shortcuts for studying vocabularies in renshuu. As it is now (using the mouse event for displaying choices, choosing an answer and showing the next question) the user experience does feel tiresome if one wants to utilize this tool for frequent repetitions of huge collections of flash cards. Anki is superior in this regard (typing [space] + [1,2,3,4] and you are good to go).
There are actually keyboard shortcuts for the review of flash cards :)
(d) - unhides/hides the multiple choice responses
(1,2,3,4) - select response 1 through 4
(enter) - next question [in case you show question and answer one after another and not side by side]
(s) - start review [on the schedule page or review results summary]
There are some more - you can find a more complete list when you hover with your mouse over the keyboard symbol directly above a quiz (besides the "End Quiz" and "Problem?" buttons).
