Many thanks for your replies and suggestions. I have been busy thinking and tinkering. I've fixed my immediate problem (unable to engage gear 1), but I am not sure of the long term consequences and I now have to face another potential problem...
I finally got my gear 1 back. The clue was that when setting the cable pulley groove in the recommended 9-10 o'clock position on the shifting shaft, hub cable 1 was significantly longer then hub cable 14 when in gear 8. Hence, when pulled to full length to try and engage gear 1 it would be stopped by the (gear 1) barrel adjuster mounted on the left chainstay. Unwinding the barrel adjuster would simply make the shifter cable too tight and hence the gears would not work at all. So, the only way I could fix this was to rotate and set the cable pulley groove c. 60 degrees anti-clockwise to the c. 8-9 o'clock position. This equaled out the lengths of the hub cables when in gear 8 and hence gave me enough room to JUST clear the barrel adjuster and engage gear 1. The Rohloff instructions and video state that the hub cables should be equal length when in gear 8 and to adjust if not, but they don't say how to? Especially as I just purchased the 'easy hub cable set' which are pre-wound/cut? I read that if the the cable straightens out to the hole where it emerges from the pulley centre, it will quickly fatigue the cable. But I am not sure if this is happening on mine? The gears work fine and are indeed already a lot smoother than before, even before I attempt to complete the job by changing the inner+outer shifter cable...
Ever since I purchased my (new) bike, I wondered why one barrel adjuster (gear 1) was rather crudely sawn off by the manufacturer/assembler (see pic 1). Well now I can guess why. They too faced the same problem of the hub cable reaching the barrel adjuster? Its root cause? The hex nut which the pulley sits on is set slightly out of alignment (hence 9-10 o'clock on mine is more like 10-11 o'oclock) AND/OR the distance from the centre of the rear axle to the centre of the barrel adjuster mount is less than the recommended 240 mm (chapter 7.2.2 / pg 79 of manual) (see pic 2). There is just not that much wiggle room. The cable has always been tight making connecting the bayonets always a struggle. The barrel adjusters were fully wound in when I received the bike and I have never been able to adjust them because -evidently- the shifter and hub cables never stretched. I've always wanted 1-2 mm more slack to free up the shifter and to make bayonet connection easier.
So what to do if , as I will have to eventually, fit new inner/outer shifter cables? I have purchased the cables, new female bayonets and new barrel adjusters just in case. Do I cut the inner/outer shifter cable the same length and replace like-for-like, or is there some way I can mitigate the problem by altering the lengths, i.e. the barrel adjusters would normally sit half wound out.
To me it seems the root cause is the barrel adjuster mount being welded too close to the hub!
I hope you're all still awake, followed me, and can make some suggestions.
Thanks very much