The unlocking the hatch without using the key I fixed by putting in a power door actuator into the hatch (horizontally) and wiring it to the rest of my power locks that I put in at the same time we put in my alarm so I could have keyless entry that locks/unlock my hatch from the remote together with my doors.
I don't have power door locks, so that's out. I just gotta remember to lock the hatch.

You are right about the small horn buttons, they do take some getting used to. I found myself slamming the airbag a few times when I was trying to honk at someone...
Yeah, I've done that! Fortunately, I only drive it about 5% of the time. My wife is reluctant to blow the horn, so it's not a problem.