On the crossing a solid white line business:
Highway Code Rule 129 says
Double white lines where the line nearest you is solid. This means you MUST NOT cross or straddle it unless it is safe and you need to enter adjoining premises or a side road. You may cross the line if necessary, provided the road is clear, to pass a stationary vehicle, or overtake a pedal cycle, horse or road maintenance vehicle, if they are travelling at 10 mph (16 km/h) or less.
That seems clear enough, until we take into consideration the 10mph thing ... I think DoT have made a mistake here, crossing the solid white line when it's safe to do so in order to overtake a cyclist should be permissible at any speed. It seems unreasonable to require vehicles to not cross the white line when following a bike at 11 mph (?)
Of course most have no clue about rule 129 anyway which makes the point moot. The worst are those who believe they must not cross the white line at all but try to squeeze past anyway.