Rolling thunder,
("7 out of eight slides deploying is not acceptable or good performance. If there are eight, all eight should deploy. It's called maintenance standards.")
Is rather like saying how do you check if a hand grenade is going to work. You cant.
The only pre-flight check of a slide raft is that the gas bottle pressure is in the green/on the dot.
Your second quote:
("Bursting tyres on touchdown raises an interesting question on braking effectiveness.")
I really dont understand where youre coming from here? Basically, on final approach with no power, those guys literally had to drop in on the runway and give themselves enough tarmac to stop the thing - the flare is an afterthought.