As a school bus driver in Calgary, because of bylaws, we do not use the eight way flashers or bus-mounted stop signs. The same goes for many municipalities in Alberta. Also, in Calgary, because of bylaws within the city, we do not stop at RR crossings, though I do slow down and cross with caution. In the country, we do stop at RR crossings.
You complain of school bus drivers not turning off their signs until all kids are seated. That is a policy of all school bus companies that I know of in most jurisdictions. and concerns the SAFETY of the passengers. It is also likely the LAW in most jurisdictions! Why? Because a child can easily fall if a bus takes off before he/she is seated. In addition, the interior lights on the bus turn off when the door is closed, so the doors are left open until the child is seated, so he/she can SEE to be seated. As sunrise was 8:13AM yesterday in Calgary and ALL my kids are picked up BEFORE 8:10AM, the earliest at 7:15AM, I do not shut the door until they are all seated and my four way flashers and strobe remain on until then, also.
AFA your comment about stopping at ALL RR crossings, that is THE LAW! (Unless the municipality passes a bylaw, like Calgary.) If car drivers are too stupid to wtch out for buses, that's THEIR problem! It's not like the buses are hidden! They are big, and yellow, and have yellow reflective tape on them. They also have red flashing lights and large signage that says something similar to "STOP WHEN RED SIGNALS FLASHING". Many also have strobe lights!
If a driver is too stupid not to read or comprehend such signage, well, maybe they shouldn't be driving. Even my 20 passenger special needs buss weighs over 4,300kg (9,500lb), so if you run into my rear end when I'm stopped, likely the most damage to me or 'my kids', might be tiny lacerations from flying safety glass. AFA the bus? A little paint damage whereas your car most likely will be sold for scrap.
In case you are upset about the speed of school buses, in Alberta, like many jurisdictions, the speed limit for a bus bearing a 'SCHOOL BUS' sign is lower than other vehicles. (For example, the speed limit on expressways in Alberta is 100-110km/hr. For a 'SCHOOL BUS' it is 90km/hr.)
When it comes to drivers running into school buses, usually, 
If you can’t understand the frustration of waiting across the street from a school bus on a busy street because the driver won’t put his stop sign in until every child is seated then I think that you are the one who is stupid. I am not talking about those unfortunate enough to be stuck behind the bus... they obviously have to wait until the all the children have finally found a seat. Although I will tell you that where we live there are plenty of spots where a bus can pull off the road to wait for children to board. They of course do not use them.
As a firefighter I responded to many motor vehicle accidents where a bus was sitting in the middle of the road because of seldom used spurs crossing the road diagonally to storage yards for many businesses who never even used them. You can blame the motorists, but this idiotic law causes more injury and mayhem than it prevents. I have no problem with busses stopping for actual crossings that do not have warning lights and gates, but stopping at crossings that have tons of safety gear and spurs going into unoccupied business yards is nothing but stupid.
Apparently kids in Calgary do not react the same way kids around here do when their bus is rear-ended. Around here even the kids know if they complain about anything they might get some kind of award from the drivers insurance company. We transport every uninjured kid that has done even the smallest amount of sniffling as a precaution and to protect the fire department from liability. It is all a giant nightmare for everyone concerned all over an idiotic law that most likely causes far more injuries and death than what it prevents. Are bus drivers really so much more stupid and unobservant than the average driver that they need this law to keep them from colliding with trains?
And for your information I too have a bus drivers license. I have it because I drive buses as a volunteer at retirement centers and church. As a fire officer I took dozens and dozens of train safety courses over the years. All I ask for is a little common sense please!