1:53s at Laguna Seca is a decent time for a sedan on the stock suspension. It can be faster, but watching the video shows that you were driving with a very good margin of safety. Good driving by the way.
It is a shame that the pads don't last that long. The good thing about RS19 is that they're the longest lasting track pads available anywhere. They were developed for Endurance Racing.
I still have 80% life left from a 4 years old set of rears, and 20% left from a set of fronts.
Castrol SRF is the best brake fluid out there. Be aware that the RS19 don't have good grip when cold, just press the brake pedal harder.
03 Celica GTS
04 Hummer H2
07 Cayman S
08 BMW M3