Tarot Card:
If you watch closely, you can see that Cutter had three Tarot cards pasted in his journal - The High Priestess, The Magician, and The Tower. (When you get Cutter's journal later, notice that the Tower card is gone...)
When Talbot takes the journal from him, they remove the Tower card and slip it into Cutter's jacket.
You can also see notes in Cutter's journal about the other cards - The High Priestess = Marlowe, The Magician = Talbot.
The Tarot is full of Hermetic symbolism, which ties into what Cutter was saying in that one scene, about the ancient secret society. And how Hermetic mysticism is all tied up in it. So planting the card on Cutter is sort of an ominous, creepy warning to him and the others. Since it predicted his own fate - or at least the fate they orchestrated for him.
Getting Shot and disappearing:
Hey - I saw people are also confused about Talbot getting shot, and disappearing... maybe I can elaborate a little...
Marlowe's crew is supposed to be a highly-trained clandestine organization, with roots stretching back to Elizabeth I and earlier. Sort of like CIA/MI6 secret intelligence service type ops... so the idea is they have lots of means to confound their enemies like a secret arm of the CIA or MI6 might, for example. Like Cutter says, manipulating their enemies through espionage, deception, fear.
This is based on real-life clandestine ops, and "the art of deception". Groups like the CIA really used magician's tricks as well as drugs, etc. to trick and frighten their enemies. So - you can assume there's a rational explanation behind these mysteries... e.g., a bulletproof vest, an escape rope/wire, whatever--which looks "magical" but has a rational explanation, just like a magician's trick.
Magic, tricks, deception, illusion, perception vs. reality - these are themes throughout the game. Abra-goddamn-cadabra.
Why it wasn't explained:
I tend to like to write stories that require interpretation, rather than laying everything out, so I'm happy to elaborate.
As far as his endurance in the chase goes, ND have said that Talbot was meant to be Drakes counterpart or foil. He has similar physical ability and endurance. So it makes since that he can match Drake and maybe even best him a little during that chase scene.