My comments aren't an analysis, it's simply how things work on a movie set. I've been on a few movie sets, and am good friends for more than 20 years with an actress who won her Academy Award for playing a serial killer.
Except in rare circumstances, actors aren't given instruction or training in firearms safety any more than they're given instruction on electrical safety or camera boom operation safety.
Often actors are taught how to fire a weapon and are of course given the requisite safety training at that time, but weapons safety is not their job on set, because live ammunition is not, or shouldn't be, a factor.
The only weapons safety instruction that actors get for on-set behavior is to never pick up a weapon off the weapons cart unless it is handed to them by a weapons master or someone else charged with weapons safety of that weapon. When an actor is handed a gun and is told it is a hot weapon, it means the gun is loaded with live blanks. If they say it's a cold gun, then the gun is either loaded with dummy rounds (that look like real bullets, except for one small detail, but do not contain any explosive material and thus cannot discharge), or nothing at all.
Baldwin was a producer at least partially responsible for hiring these people and should have been familiar with their backgrounds and their lack of expertise.
Possibly, but we don't know for sure what segments of the production he dealt with. He may have only dealt with shooting locations, or hiring the people who dealt with shooting locations. He may have only dealt with post-production editing. Who knows. But the smaller the budget, the more hands off the producers tend to be. And this movie is a pretty small budget.
Also, you can't use real world logic and safety measures in the land of make believe where live ammunition isn't even supposed to be on set in the first place. You can claim it was Baldwin's responsibility to clear the gun before firing it, and in the real world with real ammunition you're exactly right, but on a movie set that responsibility is explicitly someone else's. It's precisely why actors can point guns at cameras, people and other things they do not intend to shoot, and then pull the trigger.