I think 10 seconds is good for each turn of bottom bar, without retired drivers every other time would make it a bit faster but still giving enough time for everyone to read it.
I guess your are watching with Live Timing? 
The Nascar/IndyCar style of a top bar with numbers is illegible, since it races by most of the time. You need 3 laps of the ticker to know where everyone is.
The number of stops should always be in brackets behind the driver. It is on for minutes on end and you don't see the gaps.
I like the MotoGP sidebar, a fastest lap is shown when it happens. They add spacing when riders are more than 1-2 seconds apart (should be 5ish for F1). And better, they have four sectors instead of three. With the Tilke dromes being build for 100 second laps, a 25-45-30 second sector is a bit meagre.
