As far as I no the pitlane i closed till everyone is trapped safely behind the safety car to prevent people from instantly diving in and shooting out of the pits hurring to the back of the field driving through the danger zone like maniacs. Imagine someone hurrying back out of the pits flying by Kubica`s rescue team at last years Montreal GP and loosing it! Could have benn a huge disaster!
For sure the whole rule has to be revamped in a way, hopefully for the better...you never know in F1
...and yeah parking F1 cars are a huge problem for the engine. My thought: A : As already told before get rid of the refueling (that`s for endurance racing in my opinion). B: Get rid of the safety car completely!...and whenever a full course yellow / safety car is needed, the drivers have to use the pitlane speedlimiter (or a new limiter, let`s say 160 km/H) until everything is safe again. No marshals would be endangered and the pitlane could stay open.