I'm fairly confident that the most dangerous part of traveling with traffic is the speed gradient, regardless of which side of the spectrum a driver may fall on. If conditions are poor and 'traffic' is generally going 45, it seems just as reckless to me to go 25 as it does to go 65. It would be my hope that someone not comfortable driving with the flow of traffic in bad conditions would just not drive, as confidence (but not cockiness) is important. If someone feels that traffic is going too fast, but they are confident that their speed is reasonable, then pull over and let people by and continue at your own pace. I think most drivers recognize when someone (even themselves) is driving much too fast for traffic conditions (tailgating/intimidating, lots of lane changes, etc), but driving too slowly is also a hazard as it forces traffic through a choke point (especially if the offending driver is in a passing lane). This results in lots of extra lane changes by other drivers and the slowing down of at least two lanes of travel as a result - which I would argue is overall a more dangerous situation for everyone. Of course, this is just conjecture and opinions on my part - I'd be fascinated if someone had any data on the phenomenon.
Anyway, just don't be like my dad, who while driving down
Bethoud Pass at 5 under the speed limit created a queue of around 15 cars behind him. I suggested he use one of the [many many] pull-outs to let people pass. He replied, "Why would anyone want to go any faster than this?" and continued driving. This is now an oft-quoted phrase whenever we get stuck behind an oblivious or self-appointed pace car.