More of a curiousity question really... does Substitute block self-inflicted confusion ala Petal Dance or Thrash?

I don't think so. It wouldn't block sleep from Rest either...no, IIRC Sub really only blocks damage/effects from opponent pokemon

Hmm, I reckon Safeguard follows the same pattern? I.e. you set up Safegaurd, send out a Pokemon with Toxic/Flame Orb, the status gets applied anyway? Same with Mist and moves like Overheat?

In the summary screen there should be something indicating that they have pokerus next to the pokemon's picture. I don't remember what it is but after they stop being contagious it's a little smiley face with a flat mouth.

What are some good spots to EV train (aside from the haunted mansion for SA and Tentacool surfing for SD)? Not just for a single stat at a time, but maybe for two, like how the Power Plant in FRLG trained for Spd and SA and nothing else? Or, for that matter, areas with clusters of single- or dual-EV trainers which you've found.

Also, what're the best spots to hit rich trainers for cash?

I'm trying to EV train my Mamoswine. It's Adamant, and I want it to be a physical sweeper, natually. I hatched it from Swinub, and gave it EXP share to get it to level 33 via Pokemon League. Judging from what I've read, I may have already screwed up the EV distribution.

Should I just breed for a new Swinub and EV train at the start? Or can berries save it? If so, what berries and where might I find them?

Try this to find what you are looking for:
http://www.psypokes.com/dex/search.php?type=effort

I mean I didn't see anybody >.> We all added each other (and the other people saw each other) but they didn't see me.

I'm too lazy to test it out myself, but I'm also sure that someone has tested this already, so here it goes...

We all know that Lati@s is not banned from the WiFi Battle Tower, but does Soul Dew still work as a held item? I remember a thread somewhere in the forums that hinted at that, but I can't find it ATM. Can anyone help me here?