This is exactly the kind of answer I was looking for. Patches' PC is a great roleplay and really bright. This is also sort of his only social outlet, so I absolutely don't feel right making him uncomfortable. I don't want to solve this problem OOC.
Being a "That Guy", is not, and both Patches and you are close to being "That Guy" right now. Don't be the DM who breaks his word to a player. I mean, sorry to be harsh but you're already lying to his face by your own admission.
This was absolutely the kick in the ass that's woken me up to what's going on, and what I'm abetting in the process. Thanks. As for the lying bit, it was an attempt to sound like I've got the situation under control so I don't lose a player whose idealism and naivete has in the long run cost the party more than Patches himself has. It's been very well roleplayed to boot. I shouldn't have said that what I had planned required him to be there for a chance of success, but I am attempting to make good on that regardless. He will absolutely be an integral part of the upcoming campaign, and his sphere of knowledge will be a big part of one of the three or four plot threads I'm rolling around right now. I don't have the encounters planned, or really anything of the new country mapped out, but I originally planned to try to move the Cleric away from his religion and more toward his God, Thoth, and I very much plan to curse the entire party with undeath at some point in preparation for a meeting with the rogue God Narashe. I just have no idea how best to do it, or when the party will be ready to meet Death incarnate.
The last thing a party wants is an aimless DM that has no idea where he's going. So far, I've managed to riff enough that only the Cleric has caught on that Patches has me completely lost on what to do next. Three party members have caught on that Patches' character just got some Karma coming his way after his outburst. The Loremaster/Pyromancer's players have caught on to what's going on, and the Knight noticed I've got a tally set up on my copy of Patches' character sheet in the dropbox.
I haven't told the Knight's player about what's going on or asked his opinion, because I know he'll tell Patches' player. I only started IC punishments for Patches during today's session, what with losing a hand and then being cursed by vengeful Gypsies. I want to see if those have an effect in turning around his worsening behavior before I take it to OOC. I don't want to lose my Cleric, though, so I'm really hoping it isn't too little, too late. Patches has only been fucking up for one or two sessions at this point. Most of his other misdeeds have been purely humorous and many of them beneficial to the party.
But yeah, your advice sounds incredibly on point. I think that trial idea is absolutely splendid, but rather than leaving it up to the Cleric alone, I'll set it up so that four witnesses must speak to the character of the condemned and swear their lives in exchange for his rehabilitation before the gods. I'm actually gonna phone the Cleric later today and let him know that he's going to have the opportunity to vote on Patches' ongoing continuity with the party. Patches only survives if he's got a full change of heart during the next session or two and the party unanimously votes to let him bypass incarceration. I know three votes will go to him. The Cleric's the only uncertain one.
I just worry that this might make the game revolve too much around Patches, and not enough around the other players' wants.