I do #1 here and there.  Only with pistol though. I don't have the confidence yet for POA/POI for handgun. But when I check to see where my rounds went, I don't lower the pistol, instead I "prerrie dog".  Rifle is not an issue as I know my POA/POI is and have confidence in it.

I've seen #4 not only with shooting accuracy, but doing the drill too fast. As in running too fast.  There's 1 guy who's an accident waiting to happen. In 2 different skill builders, he was the only guy who slipped on his butt  twice.  1 time was with a empty (we didn't know if it was 100% empty or not. The RO did know because he checked  prior to him leaving the station and running back toward us)  rifle slung which as he was on his back, he was flagging the entire class.  I was wearing my plate carrier, but others weren't. They went to their car and put theirs on after this.

So with that being said, there is no need to go 100% speed.

I met a guy the other day who we were discussing the Myeni shooting and he feels HPD should have shot him in the leg or arm and not a "kill shot".  This guy is a CCW holder for out of state and waiting for HI to get their shit together b4 he applies.

I told him the Taser failed, and the cop was getting his face smashed in.  He still felt a leg or arm shot should have been done.  I explained cops are trained to shoot center mass and not leg/knee/arm shots. He said it doesn't matter.  Then I explained while Myeni was raining blows MMA style, even a leg shot would probably have gone thru and hit the cop who he was on top. So the only real if anything shot would be the arm. But now the arms are moving (raining blows), thus making it a moving target.  He said "I could hit it".

So the point is this guy also claimed he trains and believes he can get this type of shot.  I didn't want to call him a moron or explain that taking a knee/arm shot might get him or others killed/injured (others injured if he misses).

I see #1 a lot on video scenario simulators.  People either shoot once and hit and bring the gun down, or they'll shoot once and not get a hit and still bring their gun down. 

See #1 a lot and have been guilty of it in the past. Many may not even realize the are doing it, or even say that they aren't until shown a video.  It is not only a bad habit, but can have a negative impact on marksmanship.  An extension of this is getting in habit of coming off the trigger/gun quickly after a course of fire, as well as returning to holster quickly.  I see a lot of folks trying to be quick to either unload and show clear or return to holster after a course of fire.  Can lead to bad habits, including myself. 

#4 is another one.  There's a difference between pushing the pace or performance envelope and blowing past one's ability.  Some folks want to show how fast they are and don't hit crap, but "dayum they fast".  Uh, yeah, not impressed bruh. . . 

Signing up for the wrong class?  I haven't experienced that, but it's common to encounter folks that think their skills are beyond the level of the class.  One can always learn and improve, even in basic courses.  There are also those that believe they are advanced until they see someone whose demonstration leaves them 

Yup, we call that one "MeerKat"

Guilty there.
Rockette and I signed up for a "Clearing" class.
#1 There would never be a reason for us to clear our home vs wait outside for LE, at least not since were the only ones in the house
#2  Love ya but sorry Honey but you are "not the droid I'm looking for" to clear a house with.
#3  Currently would be in violation of Hawaii Law

You mean "prerrie" dogging?    

For that example of class thing, I don't think that's a bad thing.  Having the knowledge, or at least exposure to the material, is still great.  Probably lots of other useful information that you gained from a class like that.  Potential tools for the toolbox, even if some of them may not stay in there. . .