Getting the most likes from the last week is no problem as each like has a date, however, to get the most thread replies means you have to count the weekly posts from each thread, which is not ideal.
To get the most viewed threads means that you have to save each weeks results so that you may compare them to next weeks count, which in turn means the first week will not show the correct weekly count.
So, yes it can be done but not as simple as simply checking for a cut-off date.