In terms of Shoddy, I think the psycho shift situation should remain unchanged. I agree with MrIndigo, abusing a clause meant to stop abuse is just backwards. Regardless of being able to prove intent or abuse, 33% is simply too high a chance to not be a violation. Not a hard rule, but if a poke is carrying psycho shift and sleep talk, its likely bulky enough to even attempt several sleep shifts. Its a unique case that deserves a unique ruling, and I think it would be a regression from the Sleep Clause's primary purpose to allow additional sleeping this way. I really think sleep clause should also stop Mirror Coat from inducing a double sleep. Any capacity for a clause to be broken should be shut down, and since they are artificially implemented clauses anyways I see no problem in being discriminating.
Dont play wi-fi but I'd say the same rules apply. Forcing your opponent to violate a clause is about retarded, and glad to hear that the tl;dr version doesnt count that as an automatic win. If you are really worried about Effect Spore giving you that second slept pokemon, learn which moves make contact and avoid them.
I dont actually understand how that encore case can present itself. If you are slower than the sleeper, you dont encore because you fall asleep. If you are faster, you either encore a different move or your encore fails because the sleeper just switched it (and then you still cant encore its sleep). If you are a faster sleeptalker, you are put to sleep, choose sleeptalk which then selects encore and the opponent stays in, I guess you have a problem. However, in that scenario, I dont see why the sleeper would choose to stay in. Even if it did, as enigma said, it is still choosing to select the sleeping move and thusly at fault if the opponent switches. If that sleeper was the last poke available and cant switch, it hardly seems to be anybodys fault. However, if you know its your opponents last poke and you encore its sleeping move with resttalk, then switch to knowingly get slept, it is your own problem and not, in my opinion, a violation.