This is a GREAT topic... good question... the answer is, as many things in life, "it depends".
I allow two clubs to use our two farms for launching fields, and believe me, safety is a big concern for us... I TRY to attend the launches whenever I can, and I'm pretty good friends with the guys that usually end up pretty much 'in charge' of the launches, and I think we have a pretty good working relationship on that score... we all seem to be 'on the same page' when it comes to our attitudes and thoughts about safety. I try not to interfere with operations, but if I see something patently unsafe, YOU BET I'm gonna call somebody on it. If that's a problem, well, nobody's forcing them to fly here at gunpoint or anything...
Some clubs are VERY strictly operated and have very specific, formalized procedures, sign-ins, flight cards, and RSO's that you have to PROVE that your model is "safe" via inspection and/or questioning before you can fly... some are more easygoing and are only looking for 'egregious' errors or mistakes that would have little doubt of producing a bad result... Then there are some clubs (like the ones that fly out here) which are pretty small, have a core group of dedicated and experienced flyers, and don't have a formal "RSO" at all, merely club officers or advisors which sorta keep an eye on newbs and make sure they're doing what they should... If not, well, it's a club, and they'll be asked to not fly, and if they don't want to comply, they'll be asked to leave... after all, the club doesn't want to risk problems, and the landowner (me) doesn't want to risk liability... nor does the club or officers. If you're attending a club launch, well, you have to abide by the club rules, which of course are based on the model rocket safety code and/or the Tripoli HPR code. The club's NAR insurance and charter both require that the NMRSC or HPR code be followed at all times for the launch to be "covered" by insurance. Usually the club leadership has an agreement with the landowner to conduct operations according to the NMRSC or HPR code.
Now, sometimes accidents happen... there are unforeseen failures or situations crop up that cause a malfunction, like wind blowing over a pad right at launch, or a shock cord failing and causing the rocket to come in ballistic, or failure to eject or deploy, or whatever. Sometimes these are "foreseeable" conditions that happened due to mistakes, inexperience, or bad judgement. If things are being conducted with safety in mind, there should be precautions in place to minimize the risks/damage from any unforeseen malfunctions so that injury to persons or damage to property is prevented. This usually comes in the form of making sure the launching site is actually large enough to support the size/power of the rockets being flown, and laying out the launch site so that the wind is blowing across the flight line, not towards it or away from it, which could cause rockets to overfly the parking and spectator areas or the prep areas... having the correct standoff distances between the pads and the controller area/prep area/spectator area, tilting the rods a small amount away from the prep/parking area so that any rockets that DO malfunction will drop downrange into an unoccupied area, etc.
Even then, sometimes stuff happens... sometimes it's poor judgment or human error that causes things that could have been preventable to happen... I know of instances where the landowner and club had an understanding that there were to be NO sparky motor flights. The club was assisting some students launching a project for a contest, who had been told by their advisor helping them with the project NOT to buy a sparky motor, which they did ANYWAY, and then they drove several hours to attend the launch, which was the last launch before the deadline, and they HAD to fly to qualify. The club folks TOLD them sparky motors weren't allowed, but after an inevitable sob story, the club folks, against their better judgment, relented, and allowed the flight to launch on a sparky motor anyway, without the proper precautions being taken. Of course a grass fire resulted, which not only burned off the launching field, but came within feet of burning off adjacent neighboring cropland, which had yet to be harvested... a stupid mistake nearly cost hundreds of thousands of dollars of unharvested grain to be destroyed, and the club lost their field... In another situation, a club that had already crashed a rocket into an operations building and had to implement some pretty strict safety rules to fly off the gov't installation they fly from to be allowed to launch there, allowed some guy to launch a HPR rocket with shear pins, despite the fact they only had a 2500 foot waiver and shear pins aren't even needed except for very high altitude flights or high acceleration flights where drag separation might be an issue, and of course the shear pins make it a "complex model" that needs more scrutiny and precautions anyway. The rocket failed to deploy and crashed off-site, in a surrounding neighborhood, and destroyed someone's back porch canopy... thankfully they weren't under it at the time! The club had a several month standdown and had to coordinate even MORE safety rules with the gov't operator of the property... (of course the fact that they weren't following the rules established after the previous incident didn't seem to register on anybody's radar).
This sort of thing is the reason I'm solidly convinced that HPR activities should only be undertaken in REMOTE locations with a bare minimum of structures within at least a couple miles... and subsequently why I don't and won't allow HPR activities on my property... the larger rockets, especially when equipped with electronics, charges, and larger motors, are more complex, have higher energy levels and masses, and are more prone to create BIG problems when they go awry... of course other folks disagree with this stance, which is their right, but then they can always go fly somewhere else... makes no difference to me.
I hear what you're saying about Rocksim and Open Rocket... after all, "garbage in, garbage out" as they used to say, is still a valid observation... I've seen folks fly rockets that Rocksim "told" them were stable, only to have them crash spectacularly, due to as simple an oversight in the programming as setting the tube size used to calculate the stability margins incorrectly... (say figuring it based on a small LES rocket motor tube up top, instead of using the largest tube in the model to calculate the CP margin, making it appear to be a much larger ratio than it actually was). These sort of things can bite you in the butt if you're not careful, and most of the time it's VERY hard to find such mistakes until they become obvious... (afterwards). Thing is, the computer simulations ARE a VERY valuable tool, as anyone from the "pre-computer" rocketry days can attest... back then, you had basically three methods to ensure your design was stable... 1) the Barrowman method of calculating CP, which was pretty limited because it operated on simplifications of aerodynamic principles relating to shapes to "approximate" the CP location of the rocket, and was VERY limited in the shape of the rocket that it could handle. So if you're design had a weird number of fins, wingtip pods or strange shapes, then it was pretty 'hit-n-miss'. Plus, you had to be pretty good at math to use them (and a lot of folks, me included, aren't good at math). 2) the cardboard cutout "center of lateral area" method, which uses an outline of the rocket cut out of cardboard and balanced on a ruler edge to determine the approximate CP location... the balance point... but it was overly conservative-- it's the CP at the worst case scenario, an angle of attack of 90 degrees to the direction of flight (flying sideways). It tends to make rockets designed with this in mind "overstable" and prone to weathercocking and other such effects. 3) the "TLAR" method... "that looks about right", followed by a swing test on the end of a string to see if the rocket points forwards, and adding noseweight and rebalancing on the string and repeating the test until it "flies right". Usually followed by a "pray and push the button" flight somewhere as far removed as possible from everything and everybody to PROVE the rocket would fly right... (what is called a "heads up" flight today).
In the old days (80's and before) we didn't have computers or programs capable of accurately determining the CP of the rocket, and especially not capable of simulating the flight characteristics of the rocket/motor combination... (these tools were in their very infancy in the mid-late 80's and only a handful of "advanced modelers" really worked with them or could make use of them, improve them, and make them more widely available). Somehow we made it through... BUT, I can tell you I feel better about a rocket that's been designed on Rocksim or OpenRocket than the TLAR method, and I developed quite a few using the TLAR method... It's just another tool... but you're right... it can turn out bad results if one isn't careful...
Later and good luck with your project! OL JR