You can't have rugby's technology used in the same way as football unless it's to be used retrospectively, i.e. to dish out cards ro ban players for fouls.
During the game it can't be done as footballs too fluid, cricket, rugby, American sports etc. are all stop/start.
Twaddle, American football DOESN'T make heavy use of technology, frankly time between most plays isn't anything worse than the time between freekicks being given and taken in general. Its simple, but coaches get 2 red flags they can throw on the field if they want a decision questioned, the ref gets ONLY 30 seconds to look at a replay from multiple angles. If he can't see anything in 30 seconds to change his mind, decision stands, if he see's something that changes his mind in 2 seconds, or 30 seconds, he'll do so and take whatever the best action is. Its quick, its simple, its incredibly limited so barely used.
The most important thing is it IMPROVED the decision making of the ref's massively so less bad calls were made, as would happen with football if it was introduced. THe mere introduction of the technology would mean, at most 2-3 mins of stoppages for massive decisions, hardly a killer, but by being used most cheating would simply stop. Red flag to see a shirt tug at a corner, penalty, most players within weeks would stop shirt pulling, diving would be non existant as you'd get caught every single time. Most cheating would simply dissappear within weeks as you won't get away with it. Meaning a few weeks of numerous penalties and hilariously entertaining games, followed by decades of almost no cheating at all and massively improved refereeing in games. But without cheating most of the time, there would be a huge reduction in the need for video replays, meaning no delays. THeres still the odd american footie game with several red flags thrown, but theres games with none, or just 1/2 used, meaning a whole 1-2 mins increased time. But compare that to minutes of complaining, fighting, decision making, carding, carding for mouthing off about a decision and you'd probably waste less time overall. But after it settles down, with the constant threat of video replays, players would continue to tow the line and not cheat. We'd get back to football without the shirt pulling, diving and anything else dodgey that goes on.
Referee's can not see every incident "live", its not possible, even with 30 referee's you won't get the correct calls, video replay gives you a chance to see the incident again, you can't beat that, there is no better way, there won't ever be a better way.
AS for punishing ref's, i'm not for it, as for complaining, I don't see it as a problem, people should be allowed to say what they think, its ridiculous to punish people for complaining about poor decisions. But ultimately a single ref can not get everything right, no ones in the wrong here except the people refusing to introduce better methods.
Every ref makes multiple bad calls in every game, its been getting worse if you ask me, partially due to people getting better at cheating. But you drop every ref in the prem league, who the hell is going to officiate the next games exactly?
There are no better ref's to take over, if there was a magic pool of ultra ref's around the place we could bring in, they'd still make constant mistakes. As far as I know, every sport that uses ref's and no video replay, has mistakes made, basically all of them, every single sport thats introduced video replay has improved massively with few poor decisions being made.