To be perfectly honest, yeah, its still a concern. I stay pretty light on the skinny pedal when I'm in the 80. I usually don't get over 65 mph when unloaded anymore. This past weekend, my son and I made the trip up from San Diego to Pismo for Surf 'n Turf, and I tried to keep at 60-65 mph pretty much the whole way since we were loaded and had the RTT back on. It "felt" most comfortable at 55-60 mph to be honest.
I just liken it now to when I had my FJ40, and just enjoy the slow drive and I'll get there when I get there.
In my wife's stock 100, I am not as concerned, but I still do stay fairly light on the skinny pedal.
As for loading things in the cargo area, I did add a cargo net behind the second row seats. I would highly recommend some kind of barrier or net to keep cargo where it belongs just in case.