HLaB
Marie Attoinette Fan
I doubt you'd see any increase in overtaking or left hooks. From experience, doing around 30mph in a 30 limit or 40mph in a 40 limit doesn't stop most cars from overtaking & left hooking me. In fact it makes left hooking worse as most motorists don't seem to have the ability to judge the speed of a cyclist.
I think you would, up here at least, most drivers are willing to wait judge your pace before overtaking but the longer they need to wait the more frustrated they become and the more likely they are to do a daft overtake, they are more likely also to feel the time gap is big enough for them to carry out a left hook, etc. Unfortunately you do get the odd idiot who will left hook etc regardless :-(