TLD and LTK nearly ran Bond into the ground?
Naturally. LICENCE TO KILL was a flop, and that's not news. It was a definite low point in Bond history. Heck, after LICENCE TO KILL's release and lack of blockbuster success, Dalton was commenting that he thought the Bond franchise had really come to an end.
LICENCE TO KILL, in some sense, was the culmination of a slow decline in interest in Bond since MOONRAKER, which more or less covers the entirety of the Glen's run as
director. And when the franchise did try to reinvent itself with THE LIVING DAYLIGHTS and LICENCE TO KILL, Glen lacked the panache and skill as a
director to make them real successes.
What kind of film did Campell envision?
From what I've gathered, much more of a "Bond Begins" tale than eventually came to be. Craig wasn't his choice for Bond. He wanted someone much younger. He's even admitted as much, and while it's clear he's come to terms with Craig and respects his Bond a lot (and he should... Craig's performance as Bond significantly elevated CASINO ROYALE's quality, on the whole, and reflected very well on Campbell), it was clear that he wasn't in control and there was some struggle behind the scenes.