This isn't able to show any weak spots in your stroke because this data is only being recorded once every second. I think you need a Wattbike or similar to show exactly what your pedal stroke looks like. I'm not sure how to work out optimal cadence, but it sounds like something worth thinking about.
Are you talking about when you're using the Strava phone app? I haven't used it, but I'd definitely be in favour of it showing when you're starting segments and doing other smart stuff like that. I'm planning on doing a bit more Strava integration with my site too, starting with getting the Strava segments for a ride.
Thanks for your feedback!