Flying Scotsman - Watercress to York.

[Iskra]

I believe they moved her to rail 200 along with the Pullmans but of late, the chosen way is to move her in light steam with diesel traction,

I was under the impression from what was said, on another forum, that i no longer have access too, to check, that West coast don't want to operate her, and that DBC, also had concerns, mostly because Northern rail , don't have any prior experience of mainline operations as a company, whilst some of its staff may very well be very experienced steam people.

She came back from Railway 200 with a DB 66 on the front, which was an interesting sight

 

[merry]

I noticed that as it passed me at about 10mph just approaching Alton station from the Watercress Line hauled by the leading Class 43, Flying Scotsman was in steam but with cylinder drain valves open. Is that a normal condition for hauling steam locomotives around the network?

A loco in steam, even light steam, has lubrication provided to the cylinders and some other motion parts by the steam lubrication system. This allows it to be operated at normal speeds even if not actually providing power.
A loco 'cold' usually has to be dragged at low speed and with close attention to bearings etc to avoid heating up (e.g. the line i work requires a qualified rider on a cold loco to monitor it). This is hard to path on the mainline network of course, so dragging it hot is an excellent solution.