Indeed. The Swedish adaptations, I believe, were in fact actually television movies that were later released theatrically.
There's a whole hell of a leap in terms of money, time, effort and general quality that exists between that kind of production and an actual film produced for cinematic, theatrical release.
The first movie was always intended to be released in theaters. The sequels were made for television, but were given theatrical releases in certain countries like the US because of how popular the series had become.
Agreed. Just as much of the action in "Fire" is motivated by the murders that take place and their connection to Blomkvist and Millennium. Half of what Salander does in the book would otherwise make no sense if those elements were written out.
It would be a terrible mistake to write out Blomkvist. They really should recast if Craig decides not to return for the sequels.