Solution to players' breaking the rules without being verbally toxic'
What doesn't take a master's degree in psychology are some relatively simple issues you deal with in League of Legends, and other PvP games.
Implement a feature that gives players credit, separated from their honor (because it has nothing to do with it), gives a player credit for participating in matches, and reporting players for intentional game throwing. In order for this game to go into review, it will request a game moderator or equivalent to review the match.
"Every match cannot be reviewed, this will never get implemented."
- Players have to earn the ability to request someone to review the match, after playing x amount of matches. Let's say, you play 100 matches and you earn 1 reviewable report. At the moment you have zero "popularity" (trying to find a word for it), and your report isn't instantly reviewed, but over a period of time (much like the Tribunal system), it will get reviewed, and if the reviewer determines that the player was breaking the rules, according to what the reporter reported, they get that 1 reviewable report back, and some "popularity".
Similar to how it is in DotA 2, the last time I reported a player, you get 3 reports a week, and if they come back successful, it lets you know, and gives you another report.
Eventually, you play 500 matches and you have 5 reviewable reports, and X popularity. The more often that your reports come back successful, the more popularity you get, and the shorter period of time it takes for your report to be reviewed.
Eventually it gets to the point where a person no longer reviews the match, because the reporter has received a level of popularity.
"Well, a person cannot be perfect forever, it's possible people could abuse and exploit that feature"
- You are absolutely correct. When it gets the point where the person's popularity has exceeded the requirement to review a report, the person who is getting reported, has an option to review the particular match under 'review', and deem whether or not they did or did not commit such offense. If they feel the person has abused their power and reported unproperly, can appeal the decision, and have it actually reviewed.
It has to be very clear, as to which rules were broken, so we don't end up wasting anybodies time. If the reporter ends up with a false report, their popularity and their reviewable reports are removed (and they can also have this decision re-appealed). If the person who is reported, wastes time by declaring they were innocent, they get automatic 2 week suspension. Next offense 3 month suspension, third offense 1.5 year suspension.