It will be a rule for safety rather than an engineering oversight. If the fuel goes in slow you effectivey get a minimum time for pit stops, this means team have time to put the wheels on properly without rushing.
I think it was a great weekend for the new chasis, thumbs up to Skaife and the team for persevering with such a radical change; I certainly was not a believer but ended up watching all of both races, even cheering for that blouse Rick.
Both new cars did well, they will be 5x better next race and 10x better by the end of the year. Congrats in particular to everyone at Erebus for such a good showing with so little time.
On the heat, I am totally amazed they hadn't done long runs in hot weather. If you are spending millions a year, that test would be critical. I'm sure it will be sorted for next race though.