The “tit” on the left side of the magazine is what engages the slide stop to lock the slide back when the magazine is empty. The fix is a new magazine.

The trigger is adjustable but it’s a little more complicated than an adjustment screw. Use the search function here or on google. The model 41 was designed as a target pistol so the trigger is intentionally light.

I do not dry fire any 22lr and I don’t know if the model 41 is ok to dry fire or not.

“It has a magazine extension”. I’ve never heard of of one for the M41. Please post some pictures or a better description so we can answer your question.

The model 41 is my favorite 22 handgun. I hope you enjoy yours as much as I do mine.