I'll put myself out there... feel free to offer suggestions...
Based on things I was taught and things I've observed over the years...
1- keep pace with traffic, the person who's insistent on going faster or slower is the hazard, but not the victim often enough.
2- when in the left lane, set the pace or follow, but definitely get the hell out of the way if you're the roadblock.
3- when merging, it is your responsibility to blend into traffic, jumping in front while driving slow causes a lot of others to have to make sudden (potentially dangerous) corrections. Drag racing to beat the vehicle with right of way is stupid too.
I never ever stop to wave someone in, I always try to leave a gap if I've already stopped so they can "zipper" in (I only wave at them if they have no option to do something foolish)... too often the "nice person" who just let someone in causes the line behind them to have to slam brakes (I often show my appreciation with a single finger, maybe that will help them learn).
I don't remember the last time I did triple digits, but freely admit to doing 90 on my last interstate road trip... not the whole way, but when that was the speed of the lane. I do tend to cross 80 on a deserted highway if I'm not paying attention... but I just saw a trooper pull over someone for speeding for the first time in years. Florida, and particularly around Orlando hasn't had any meaningful traffic enforcement for years.
I hate cruise control, and prefer a steady pedal... my DD likes to constantly shift over the small rises when cruising 70-80 mph range. I've never trusted cruise during poor weather conditions either.