RE: Stevens 200 trigger
Yes it can be adjusted. The 200 trigger is simply the old Savage trigger system with out the accutrigger. There is a screw to adjust the trigger weight spring. You can lighten the pull with this screw. The trigger spring is the small 'L' shaped bar on the side.
I wouldn't reccomend that you do anything else unless you know what you are doing as the safety and trigger system are all interconnected and all must be set properly to assure safe operation of the firearm.