The scene with the disastrous ED-209 demonstration where the malfunctioning robot shoots a board member. It's only later when it occurs to you, "Hey, who was the moron who loaded that demonstration robot with live ammunition?"
Fridge Brilliance: Which slimy corporate suit has reason to sabotage the project? That's right, Morton, the one that shortly afterwards has a good cop - Murphy - butchered so he has a test subject for his project.
Another possible Fridge Brilliance: Dick Jones is so morally lacking and confident he might as well have ordered this himself. Seeing the reaction from all the co-workers in the bathroom would explain why nobody would talk back.
The board member could have been a whistle-blower or someone else undesirable to the rest of the board, and ED-209 was an easy way of eliminating him under cover of a "malfunction."
Why would they show the flawed prototype RoboCop 2s?
With Robocop essentially being a successful, if controversial product with the guy who spearheaded the project dead, they'd need to make more. Just as Dick Jones unveiled the ED 209 to the board, the Old Man would undoubtedly want a progress report - it is his company and his money, after all. As such, they're kind-of obligated to show him how things are going.
Wouldn't the convenience store robber have had to be just as strong as Robocop to hold his rifle steady while Robocop bent the barrel?
Most likely he had a rage and shock fueled death-grip on it.
No matter how tight one's grip, adrenaline alone can't give someone the strength to do what takes a hydraulically-driven machine well over 5000 pounds of energy to do. Since The Dark Knight made this exact same mistake, it's 99.9999% more likely that Hollywood writers simply don't know what leverage is.
One of Boddicker's men is holding a grenade launcher and has a clear shot at Robocop who's distracted by Boddicker. He puts down his grenade launcher and goes to activate a crane so he can dump a ton of scrap metal on Robocop instead of using the weapon that he was specifically given to kill Robocop with. Unless he was out of ammo, that was a pretty boneheaded move.
Boddicker was close enough to Robocop that he could have been seriously injured or killed by the explosion or flying shrapnel. The guy was putting Boddicker's safety ahead of killing Robocop; the gang as a whole seem to be close, and at the very least, Boddicker's the one with friends in high places that makes him so successful. Besides, Robocop was immobilized by the scrap metal and thus an easier target.
If Murphy's wife and son moved away from Detroit after his "death" and left their vacant house to be sold, why didn't the realtors who installed those video-screens promoting its sale also clean up that abandoned debris in the kitchen? Finding a cracked mug and a bunch of burnt photos and dead houseplants lying around on the countertops sure isn't going to appeal to potential buyers who stop in for a tour.
The movie started off bad, then it got worse for Robocop, a law officer named Murphy.
The reason why ED-209 shot Kinney even after he put the gun down: the robot says "put down your weapon," and Kinney throws it away. ED-209's sensors did not register Kinney's motion as setting the gun down as instructed, so, to ED-209, Kinney hadn't complied and still had the gun. This is why Robo operates better; his human brain can make these distinctions without deliberate programing.
A less obvious one, when Robo determines that yes, taking the CEO hostage is a valid immediate termination offence and thereby rescinds Directive Four as it relates to Dick Jones. ED-209 would not have the wherewithal to process that kind of information and determination (which is easy enough for a human, but as yet still difficult for a computer to figure out.)
From a corporate stand-point, Dick Jones' "guaranteed military sales, 25 years of spare parts, renovation programs" plan for the ED-209 turns out to be much more solid than Bob Morton's: Robocop is not cost effective, he's irreplaceable, and needs millions of dollars of maintenance every year. Meanwhile ED-209, while not very good at police duty, is a capable (and easily manufactured) sentry bot and widely employed as security/military drones. Even its toys are very popular and sought-after in the real world!
Then again, the hunk-o-junk can't even climb a flight of stairs. Urban pacification is one thing, actually busting crime with it would be impossible with such a limitation. "Who cares if it works", indeed.
Also, it's only in the second film that Robocop is shown to be irreplacable; from what the first film shows us, there's nothing stopping them from just reviving other dead cops the same way as Murphy.
Maybe his operating costs are so high because all the massive property damage he does is included in the figure. They probably didn't intend to need to repair him as often as they do, either, and the holding-cell setup doesn't look like it would cost that much to operate once the initial equipment is there. They probably originally estimated him costing them far less, just a few technicians' salaries plus occasional parts. Robo's also great for their public image because his humanoid appearance makes him much more marketable, and you can let him play with the kids without worrying about him shooting them into a bloody pulp.
Public servants are forbidden to strike. However, the police are a subsidiary of a private company and overseen by the villain who has no regard for them. The strike is in fact useful to both parties as Jones doesn't need to worry about any police coming to Murphy's rescue and interfering with Boddicker. Robocop himself does not have to worry about innocent cops getting in his way or being stopped from doing his duty by the police retrieving him and shutting him down.
Reality Is Unrealistic: Police strikes have occurred before despite this, though they are somewhat rare. A notable example would be the Baltimore police strike in 1974. The main difference there was it was following a larger municipal strike by other city departments, the entire department didn't walk out, and the obvious issue of the police derpartment in the movie being privately owned. Still, realistically you would expect some form of government response, even if it only amounted to condemning the strike and requesting outside help from other police departments.
This is even somewhat hinted at in the movie, with Dick Jones stating that the strike "could really work for [OCP]." By the sequel, the executives at OCP are even prolonging the strike by cutting pensions, hoping that the actual Detroit police department will eventually be all but defunct in order for them to replace it with Robocop units.
Regarding ED-209's significant flaws, it would actually not be nearly as problematic a design if deployed in certain situations which could either be more tightly controlled (acting as a sentry in a fenced-off area such as the storage yard in Robocop 3) or where the use of force is much more encouraged (military operations, especially if they can utilize some sort of Identification Friend or Foe system to avoid friendly fire — Dick Jones even says he's looking to deploy it militarily). Police work itself is very distinct and specialized apart from military and security operations, even if there is some overlap. Even the problem with being unable to get up if it falls over just means OCP has the opportunity to sell the military recovery vehicles to get ED-209s back on their feet, similarly to how the military has specialized vehicles for recovering damaged or immobilized armored vehicles.