Im sorry this is complete and utter nonsense. I had a game about 3 months ago now. U17s. Player was clean through on goal from a big lob by a defender, there are about 20-30 seconds left with the team who are through on goal 2-0 up. Last defender pulls back the striker on the edge of the box. Had no hesitation at blowing for a free kick and dismissing the player for DOGSO. No one argued or moaned. Parents, spectators, both coaches all accepted it. Even the young lad himself went 'im off ref' before I showed the card. So everyone did agree that it was a red card......I believe it would have created more comments not sending him off.
Your last sentance 'i'd rather 22 happy players and handshakes all round' utter nonsense. You as the referee are NOT on that pitch to make people happy. You are there to enforce the laws of the game, which as you have stated you do not. If you feel something is a red card.....partic DOGSO(None of this technical bull that you go on about) then you show the red card regardless of score, time, and however many players, coaches and parents don't want a red card.
A good referee is not refereeing to make friends. Yes in an ideal world we want to be liked.....but don't be liked for being a pushover and not showing cards that should be shown. Be liked for enforcing the laws properly and getting the big decisions correct. At the end of the day the losing team probably won't like you anyway. Your actions are not doing your colleagues any favours. As others have said if you wouldn't do these things when being assessed you should not be doing them EVER.
The fact I have had to comment on this at 03:20 in the morning after a long shift at work(work in a pub) shows what complete rubbish these comments of yours are.