My thoughts on tailgating/speeding:
Being tailgated is no fun because it puts you under pressure and means that you're more likely to make mistakes, simply because this other driver is up your bum.
Unless you are an ambulance driver or something, you have no need to tailgate/go a huge amount faster than the speed limit anyway, because, well, whatever is at the other end of your journey is really not that vital.
HOWEVER, in the interests of practicality, if you are being tailgated then it's best to allow the tailgater to pass you at a relatively safe point, because then they are Far Away From You and whatever accident they cause won't involve you.
Breaking the arbitrary speed limits set by the law is not inherently bad or idiotic, but when you decide what speed to go at, you should consider these things:
a) How fast are the cars around you driving? Drive 10mph slower than everyone else, especially on a road without many lanes, and you'll become the head of a queue of increasingly frustrated cars that might try to overtake you dangerously. Drive too fast and you'll just have to pull up short a quarter mile further up the road.
b) What is your safe stopping distance? Preferably without having to jam the brakes on and give everyone in your car whiplash. Regardless of the speed limit, it's incredibly foolish to drive so fast that if a hazard (kid/cow/bicycle in road, somebody else crashed up ahead, portal to a parallel dimension appeared, whatever) appeared at the farthest away point that you can see, you could not stop before you reach it. This is why it is much safer to drive at 80mph on a wide, straight motorway/highway than on some tiny rural back road that's incredibly narrow with tall hedges and 6513515 twists and turns. I drive at 20mph on the second of those, even though most of them are technically national speed limit here in England. (For those of you that don't know what that means, that means I could TECHNICALLY legally go at 60mph on the road I live off, despite it being a steep slope with a large number of blind bends that occasionally features horses, cyclists, wide vehicles coming the other way, and even the occasional deer. Legal =/= sensible when it comes to driving.)
c) How efficient is it to go at that speed? I think it's actually more fuel efficient to travel at 55mph than at 70mph, and if you're coming up to some traffic lights (stoplights?), then if you slow down gradually and smoothly from further away, they might have changed by the time you get there and you won't even have to stop, whereas if you whiz up to the line while they're on red then you'll have to brake hard and go right down to first gear.
So yeah, I don't get why the tailgating types need to go quite so fast. But ultimately, how I respond to them is nothing to do with being right or making them have a particular feeling, but is instead to do with making sure I am safe from their idiotic behaviour.