False. Robert Forward has a technique for deceleration for interstellar lightsail craft, which is described in Rocheworld and one of his science books. Magsails using beamed particle propulsion can also exploit the interstellar medium to decelerate without onboard fuel.
Not an issue for flybys, but an issue if you want to get into an orbit.
Carrying a small rocket for a circularization burn is vastly cheaper than a 1st stage. This is covered in Jordin Kare's modular laser launch proposal, and this technique was also considered for Bull's light gas space gun. Those can produce launch economics approaching those of space elevators.
Sorry, but you're citing a science fiction author as proposing a credible method, yet don't even state what that method is.
Yes, I know Robert Forward used to work in aerospace, but his fiction writings are... fiction. He's been out of the industry since 2002 and a hand-wavy "he has a technique" doesn't strike me as being particularly credible.
(I was thinking of free-space skyhooks, exchanging momentum between inbound and outbound trips, but the ones for planets are also cool. Just harder when the planet is heavy like Earth and Venus.)
Not an issue for flybys, but an issue if you want to get into an orbit.