As I say I don't oppose it and it simply comes down to how it works in operation. What you describe is how people would like to see it working. That is the whole purpose of the trials afterall. I just don't think anybody can say with any certainty either way at present and we should tread carefully. You hear people say "its ridiculous we don't have video referrals in this day and age". I disagree because there are very real problems with interjecting into the game. We have something fantastic that has worked for a very long time. Before we go making changes that could completely ruin the spectacle, we should make sure it is 100% going to IMPROVE the game. That is what it is about afterall. If it simply means that we get more correct decisions, but we have to pay a price elsewhere, then that doesn't mean we have improved the game. It just means we've changed it.
I just know as an avid rugby fan, the game is starting to suffer a little from it. Some don't think so mind, but some think it is. Some of the delays around TMO's have become ridiculous. The world cup in 2015 was basically ruined as a spectacle for many fans. It was operating at something like 28-33 per cent of stoppages being down to waiting for video decisions. If that happens in football, then for me personally, they can shove it up their arse.
I think if we limited it to goals or offsides it could maybe work. It really does down to the parameters also. If a referee misses a foul in the build up to a goal, and the goal is checked, but the reason for it being checked is ok. Do we then go back to earlier in the move to where the foul occurred and disallow the goal? How far back? As I say I haven't read through the whole parameters of it, but its an absolute minefield in football if not set correctly.
I suppose the other thing for me is I don't have a massive problem with wrong decisions. Human error doesn't really piss me off that much unless its an absolutely ridiculous clanger. They are few and far between though.