I think it's very difficult to generalise about road position. There's parts of my commute where I'm as far left as possible and parts where I'll take more share of the road. I'll move around to avoid poor road surfaces and will happily overtake on the inside or outside of traffic depending on where the gaps are. If I'm moving at the same speed as traffic I'll ride anywhere on the road I want.
The hazard of overtaking or undertaking stationary traffic is often peds crossing the road between vehicles without looking. The other big hazard is drivers being courteous and leaving gaps for people to pull in or out of junctions- that needs a combination of good observation and occasionally spider sense.
Only 1 person seemed to have 'fessed up to having fun. For me the urban part of my commute is 'playing with the cars'