When I fly with a bike, I have a 50 pound or 23 kg limit per checked bag. I bring two checked bags, the bike is one of them. I often move a few parts, like saddle and pedals and rear rack to my second checked bag to make the weight limit. I am using an S&S case, not a cardboard box. But the same concept applies, move some weight from one to the other to make your weight limit.
If the bike box is your only checked item, everything else in a carry on bag, then I have no suggestion.
When you are used to derailleurs, you are used to time shift cables and shifters that are indexed to a specific position. Rohloff, you need to keep the cables loose. On my Nomad Mk II, I have enough play in my cables so that if I am in gear 10, my shifter could be anywhere from 9.5 to 10.5. Too tight and it might not shift right.
Keep the Sherpa too. I still have my Sherpa and for some tours have used it instead of my Rohloff bike. For some tours I prefer derailleur gearing over the Rohloff.
Is this it?
https://www.ebay.co.uk/itm/326616701130If so:
That hub is quite old to have the decal on it. The decal has the original serial number, so do not remove it. But it looks like the flange support rings have been installed, which is good.
A five arm 110mm chainring is easy to change if you want to use higher or lower gearing than it currently has.
If the sprocket is threaded, I do not see the sprocket removal tool in the photos. Photo includes an S&S wrench, not sure why since it has no couplers.
I know a lot of people on this forum really push a chain glider, but I am quite content to use a naked chain. But I like a bash guard on the crankset on my Rohloff bike.
I am not sure what kind of rear rack that is, I am quite content with a Tubus Logo EVO on my Nomad Mk II.
Looks like it has a dropper seatpost, not sure why you would need one. I would be temped to use a regular one.
Great that it came with a dynohub.