1. Do the replay officials get to watch the replay in slow motion, or do they have to watch at regular speed?
2. Is there any provision for the decision to be overturned only when a "clear and obvious error" has to be spotted?
Personally, in line with question #2, I'd have a provision if the replay official or match official haven't seen enough to overturn a call within 60 seconds of the match being stopped, the call will be considered correct and the match restarted.
The VAR officials watch replays at regular and/or slow mo speed. If we start putting time limits in, then a wrong decision can stand, which defeats the whole purpose of having the system.
Offside and mistaken identity calls are clear and obvious. Subjective decisions are less so, but have usually enough evidence to justify the final decision.
Just one example. The mancs had 4 games at home last season with VAR. One game needed VAR to overturn the usual "offside" goal given against the away team. Another game saw a manc get a red card. Another game saw VAR required to confirm a goal for the away team, and the mancs lost the game on penalties.
When we face them in October, it will be the very first time we go there, knowing that we are protected against clear errors by refs in that dump, that we have had to take every single year, up to and including last season. Refs can't say they "didn't see it", if there is something for them to see, they will see it. There is now a back up system ready and available to use when it's needed.