I think you're right and you're wrong. Yes, they've severely cut what they could have shot, but IMO they've largely cut what they did not need to shoot. If you wanted an exact retelling of the original you'd need at least another two movies-worth. Given that movies are now shown - at least in the UK - without an intermission, the maximum length of a film is now determined by the bladder, not the director. Fortunately, TTT has an inbuilt bladder-break for those with a Clue.

Further, they may have chosen B-list (to Americans) actors, but to Brits and others outside the US, many actors are A-list (Sean Bean being a primary example for Brits). I will agree that Sean Bean would have been better cast as someone who survives all three films - perhaps as Aragorn himself.

Also, B-list actors they may be, but remember that all A-list actors were B-list at one time, and there have been some A-list performances, and I'll cite Gollum/Serkis and Boromir/Bean.

Yes there's a budget, but is that a bad thing? Do we really want to see the same old faces giving the same old (though excellent) performances? Or do we wat to let the movie companies make a profit and give up-and-coming actos and character actors an opportunity? Be fair: if they weren't good, they wouldn't have got the job in the first place.

With specific regards to Theoden, Sean Connery would have been perfect for the role, but he could not have been reduced to a cameo, and would have stolen the show anyway.