I too renewed my previous Senior Railcard before it expired, and this was fine - on trains.  But on my Oyster^▸ (Smartcard system used by passengers on Transport for London services) card there was a problem.

The new railcard had a validity that was a few days longer than three years.  In that short period after getting the new card I was visiting London with my brand new card and I asked a TfL^» (Transport for London - about) person to add the new card to my Oyster card.  Alas they couldn't - machine said no.  They found an expert, who explained that the Oyster system only accepts a railcard expiry date no more than three years in the future.  Fortunately they also had a workaround: they entered the expiry date as two years in the future, and asked me to come back some time in the next two years to have the true expiry date added.

An small industrial paternoster lift that is alive and well and can be seen in the branch of McDonalds on Praed Street nearly opposite Paddington station.  It lifts food from the kitchen in the basement.  It's new - it would have been installed in the past year or so when the branch was opened.  The floor of each lift platform is like a comb, which passes through a fixed facing comb at servery level, and the food item gently slides from the platform to a holding area, from which staff assemble the the customer's order.  I was impressed at how this makes excellent use of space in the confined site.

It's on RTT^» (Real Time Trains - website) so it must be real https://www.realtimetrains.co.uk/service/gb-nr:S73184/2024-12-24/detailed#allox_id=0

I can think of a couple of reasons reason for the fingers to be on the ship.  Firstly, to avoid the ship having to be aligned precisely with fixed fingers at the port, and then stay aligned even in rough weather.  Secondly, if they are on the ship they are certain to be as wide as the loading door and thus maximise the speed of loading and unloading, whereas if they are on the shore and want to be efficiently wide they will have to be of variable width to fit the full range of ships that might use the port.   

I have a feeling, without checking a map, that Scotland tends to be the left (ie west) of England, so I'd plump for Arisaig.  I do know that the westernmost point on the British mainland is in Scotland, on the Ardnamurchan Peninsula - and a long journey it was to get there when I visited many years ago.

Without looking things up there is only one that I think I know.
8. Financial crashes.

3 looks like a protection device relating to third rail.  Either to detect a train which has something low-hanging that would make unintended contact with the third rail section that it is approaching (1000 A at 750 V is not good if you're not expecting it), or to detect a train whose third rail shoe hasn't been raised when it leaves a third rail section.

I too scratched my head on that.  I believe it's deliberate because surely Graham will have double-checked his typing!  What I'm wondering is why 2 & 3 isn't there as well - perhaps it's among the deliberate omissions.

I'll guess Heath High Level and Heath Low Level.  I know that you can't buy a ticket between Catford and Catford Bridge (Geoff Marshall made a video about this), and the Heaths are similarly close to each other.
[Edit: probably the wrong answer because they are probably TfW rather than GWR, doh]

6. Looks like Flam in Norway, which is the terminus of the Flam branch railway down from the main line in the hills.  Tip: if you sail in to Flam you should get up early and get to the station in time for the first train of the day and buy an ordinary ticket, which is cheaper than booking a group excursion from the ship.

Wow! - that is a splendid and eclectic list!

I'll claim the lowest score of anyone.  I've visited only three places: Bucharest (airport), Lecce (outstanding architecture and so few tourists), and Wick (along with Thurso, on a damp day trip by train from Inverness).

As for 'where is it?', I've some idea for most of them, but to put a pin on a map I'd only be confident for 20.

5.  I'll go for Tyndrum (Lower and Upper).  I've been through both, though not set foot on the platforms.  This was on an excellent holiday many years ago using a rover ticket and changing trains at Crianlarich between the two West Highland branches.

10.  Canal tunnels.  I know that Sapperton has a famous railway tunnel which is still in use - I travelled through it last week - and it also has a famous canal tunnel which is blocked by roof falls but which still has elegant portals - I've seen them.  Mr Google shows that the other three locations also have canal
tunnels.

Try as I might I can't see Charles Tyson Yerkes.  (OK, I confess that I'm a fan of Jago Hazzard's YouTube videos, in which CTY is frequently mentioned, often along with a mention of his financial 'reputation'.)

Row 1, column 5: our very own Mark Hopwood if I'm not very much mistaken.  His face is fresh in my memory from watching Geoff Marshall's recent YouTube video of the Marlow branch starring Geoff, Mark and the branch's signalling technology.