In the same way that footballers wave imaginary yellow cards at the referees?
Yes the attempts to influence the umpires breaks the code of sportsmanship.
It was silly re the light, cricket seems to have wrapped itself up in red tape like the "umpire's call" on the DRS and the rules governing light referring to a perceived threat to the players.
The only real threats to the wellbeing of the players is being hit by the ball, and so bowlers need to keep it up on a length and no fielders close in in front of the batsman should reduce the danger to virtually zero.
As someone else (BarmyArmy?) mentioned, they should start earlier in the day to make up lost overs. Didn't help with the late start, in the modern era with millions made on such events you'd think they'd have state of the art undersoil heating, drainage and cover for the wicket.
Of course the over rate is the big issue, what with time taken up by unnecessary drinks breaks, regular field (re)settings, trudging back to bowling marks, reviews and some time wasting
- drinks breaks are unnecessary in some English conditions, fielders could get a drink any time more or less at the boundary edge and umpires could carry a thermos or four for themselves and batsmen - batsmen may have been out there the whole hour or a few minutes
- field settings should be limited to while the bowler is making his way back to his mark, if a spinner then less time allowed. Give them 10-15 seconds between deliveries, maybe 5 seconds longer if a left-right switch for the batsman. Trudging back to bowling marks would be regulated by a time limit between deliveries, I think they have something like that in tennis don't they now?
Nothing much you can do about reviews taking time, they happen when a wicket falls or might fall so you can just make sure the next batsman is at the boundary edge by the time the review is completed. No drinks breaks, formal or impromptu, should cut out time enough wasted to get one over an hour extra in without killing the players or umpires. Hell they have enough things out with them as it is, are water/drinks bottles much more consuming of space or heavy to carry than fielding helmets etc?