There may not be much point, putting in my oar this late, but I think it is important to counter certain misapprehensions. The paraphrased moderator responses don’t sound like anyone I’ve interacted with and certainly don’t reflect my approach to the task. And to say this,
…is to contradict the more positive statements made elsewhere in the post. Nobody is free to hurt others. As far as I know, all bad behavior that the mods know about, whether by report or witnessed, is dealt with. Of course, how it is dealt with may differ from what the reporter expects, based on the offense, the player’s record, and whether the player has been warned before. All bad behavior, even minor offenses like escaping, can result in a ban if done habitually.
The OP’s suggestion of temporary bans already exists indirectly in the form of an appeal. If a player appeals and promises to reform, the ban might be rescinded (i.e., it was effectively temporary). This happens with some frequency on chat bans, and sometimes the player really does reform.
I can’t speak for the other moderators, but this is my approach in dealing with first offenses: if a player is new (I know, they may be a sandbagger or new only to OGS—no matter), with fewer than 50 games, and they stall, escape, or won’t accept the score, then I explain go etiquette to them. If they are experienced, they get a warning. Score cheating and sandbagging are treated more severely.
Here is the interesting part. Roughly 50% of beginners react positively to the explanation, apologizing and/or explaining that they are new. Most of the others don’t respond, which is fine so long as they stop the behavior. About 90% of experienced players, however, just ignore the warning. Perhaps 10% at most actually modify their behavior at least temporarily. In both categories a few react with vile abuse.