From Morzeny's reaction here, we get the impression that Grant killed his target in record time. This introductory scene shows us that Grant will be a force for Bond to reckon with, a man who might prevail in a fight to the death.
KRONSTEEN: My reading of the British mentality is that they always treat a trap as a challenge.
You might consider Bond a personification of the British mentality, and if so, Kronsteen is right on. When Bond's caught in a trap, which happens all too often, his cleverness and strength often help him bust out of it.
BEY: Two girls who love the same man want to kill each other. It must be settled the Gypsy way. As I'm a family friend, I think we'll be allowed to stay.
In some context, perhaps the Romani girlfight is supposed to be honorable. The girl with the most strength and skill wins. However, as it's presented here, it appears to be intended to titillate the mostly male audience. The fight is less about skill and more about two women tearing each other's clothes off to win the approval of a man.
TANIA: James, you are hurting me!
BOND: I'll do worse if you don't tell me!
Bond feels that Tania has betrayed him, so he treats her the way he'd treat anyone who crosses him: he smacks her around. This is seen as nothing out of the ordinary at the time. Bond's violence doesn't even make Tania feel like he doesn't love her. This is one way to portray masculine "strength," we guess.
GRANT/NASH: My orders are to kill you and deliver the Lektor. How I do it is my business. It'll be slow and painful.
Grant's SPECTRE coaching undoubtedly included long, grueling, and often life-threatening training routines. As a result, the guy's very strong, and he's ready to show off his strength to take down Bond. Their fight is intense, and many times Grant has the upper hand. Bond isn't stronger, but he's able to outwit Grant with his gadgets.