Im very interested in the fact that you went out of your way to find trouble on a darkrp gmod server. You joined the server looking to cause problems just to tell someone "ItS nOt In ThE RuLeS" I have spectated alot of sits and never hear anyone using the "Staff members reserve the right to use their best judgement when dealing with infractions not mentioned in the MOTD. Do not question their authority" excuse. The screenshot you posted of someone getting muted is not even remotely relevant because you do not know what fully happened. I was in a call with Bio when this happened and it was not a perma mute or a 1 hour mute, it was a simple 2 or 1 minute mute to have the guy chill out. One may view this as a punishment for "Staff diss" but in reality, if you view that as a hard punishment, than i would hate to see what other punishments are classified as. You framed that image in a sense of this man just got a 4 hour over staff diss.
Addressing the common used ban reasons - They are all common sense.
NITRP - I was on the server 2 days ago and there was a SWAT member who was stun sticking people onto a rooftop for about 20 min. Later went on just to randomly taze people for no reason, and even started building on the streets. This is clear NITRP. Every situation regarding NITRP happens in this manor, players dont play or dick around and get banned. No one else is at fault but themselfs. If you do not know what NITRP then you prolly should not be playing on a server. We do not need guidelines for every little thing on the server. People have brains, they can turn them on and use them every once in a while.
FailRP - This is prolly the most simple one at of them all. You do something your role is not meant to do. Ex - swat raids a base for personal printers, or hitmen place a hit on hobo etc. No explanation there, everyone knows that rule.
Staff disrespect - Out of everything you said in that entire passage I slightly, ever so slightly agree with this one. Some staff handle disrespect in different ways. Some brush it me, others do get offended by it. We do say during orientations and introductions to staffing that disrespect is not punishable. Why? Well its the fucking internet. Now there is a difference between staff diss and harassment, which are often confused. Harassment is causing problems endlessly for someone on the server, and regardless if your a player or staff member, we will step in when harassment takes place. No staff nor player should have to deal with someone or multitude of people shit talking them endlessly on the sever when taking tickets or even just chilling out. So staff diss and harassment are different, but please know the difference.
In conclusion i would like to say that just about everything you stated should be dealt with could have been handled if people just used common sense. We are not making a 98 page MOTD specifying every little thing players can and cannot do at each role, as that is ridiculous. We can all open our thinking caps and put them on for a little bit and understand that "hey maybe what im doing is not specifically said, but i sure know its not allowed". Either way, you came here to start trouble in game, which is enough for many people to get frustrated with working with you.
I am not, and will not get into an argument over this on the forums, feel free to pm me, but i more than likely wont respond to this if you choice to.
(dont know how you viewed this but its not meant as malicious intent, im just simply giving imput and responding. Also pardon any spelling mistakes)