There are a couple of points I'd have to disagree with you.
- Firstly, I'd bet that several report options, especially the "unskilled player" one, are just placebo that do nothing, and provides the upset player a scapegoat to fire on, without negatively affect anything. A rather nice solution actually.
- There IS a minimum time requirement that you have to spend on each case (90 seconds, I think). People who punishes every case and run 90% accuracy on the league table could mean that, the priori of a player getting to Tribunal being banned is 90%. Which means that the automate system that put up Tribunal cases are doing a great job! Of course there could be other explanation. But I recalled Riots used to have a "pardon day" that they actively asked banned player to post in a thread, so that a human will actively review the cases. I don't think more than a dozen accounts were really edge cases.
- There are an option when you create new account to choose which type of players you are (there were 3 of them: new to MOBA, new to League, experienced, I think). I don't think it helped the smurf situation at all. The type of players that are banned would be more likely to be the type of players that like to "pwn" new players.
- There are a tip that says "Your teammate performs worse if you harass them"
- Adding the dice roll for the game is infeasible, for the reason that the metagame's roles (top, ad, support, mid, and even the jungle in the past) are created by the players, not Riot. Unlike WOW, in which roles (tank, healer, dps) are specifically designed by Blizzard, the roles in League are strongly defined by the metagame at the time. It's not that Riot doesn't design a champion with a specific set of characteristics in mind, it's just that the range of role a champion can do varies quite a bit: in WoW, a dps trying to tank will be killed in half a second. In League, we used to have mainstream range AD mid, tanky mid, caster mid, assassin AD mid, teemo mid etc. There's no way to meaningfully classify "roles" or even "lanes" position properly - who knows if one day we might have 1 - 3 - 1 laning like dota?
I was about to make most of those points, but in terms of meta... there are exactly four gold streams (3 lanes + jungle). They could have people roll for one of those. And no, pickpocket does not count as a real gold stream, any more than GP10s do. I say that as a support Janna main.
Yes, there have been a few crazy strats, like the tournament game with the "jungle" Heimerdinger where they ran a push comp after their opponent picks had boxed the other team into a corner, but that sort of thing requires team coordination, in which case you're not worried about calling roles in the first place.
Matchmaking is a real problem and it sets people up for failure. There are plenty of people who are simply not prepared to jungle or support. Or, heck, depending on their lack of runes, they might not be able to tank, AP or ADC. You can say "you don't really need runes" but when you have little practice already, going in unprepared is only going to make it worse. I've supported without GP10s due to forgetting to change from a full ADC setup in champ select. It's painful, sightstone or no sightstone to be that poor, even if it was hilarious to ignite a poor, unsuspecting enemy Sona for first blood at level 1.
- There IS a minimum time requirement that you have to spend on each case (90 seconds, I think). People who punishes every case and run 90% accuracy on the league table could mean that, the priori of a player getting to Tribunal being banned is 90%. Which means that the automate system that put up Tribunal cases are doing a great job! Of course there could be other explanation. But I recalled Riots used to have a "pardon day" that they actively asked banned player to post in a thread, so that a human will actively review the cases. I don't think more than a dozen accounts were really edge cases.
- There are an option when you create new account to choose which type of players you are (there were 3 of them: new to MOBA, new to League, experienced, I think). I don't think it helped the smurf situation at all. The type of players that are banned would be more likely to be the type of players that like to "pwn" new players.
- There are a tip that says "Your teammate performs worse if you harass them"
- Adding the dice roll for the game is infeasible, for the reason that the metagame's roles (top, ad, support, mid, and even the jungle in the past) are created by the players, not Riot. Unlike WOW, in which roles (tank, healer, dps) are specifically designed by Blizzard, the roles in League are strongly defined by the metagame at the time. It's not that Riot doesn't design a champion with a specific set of characteristics in mind, it's just that the range of role a champion can do varies quite a bit: in WoW, a dps trying to tank will be killed in half a second. In League, we used to have mainstream range AD mid, tanky mid, caster mid, assassin AD mid, teemo mid etc. There's no way to meaningfully classify "roles" or even "lanes" position properly - who knows if one day we might have 1 - 3 - 1 laning like dota?