Here's the upshot.
No Alignment restrictions. However, I think we'd all like to keep Playerkilling to a minemum (IE, No PvP under most circumstances).
As far as out of adventure stuff, pretty much anything out of an adventure happens in the Tavern thread. If you're talking privately, simply Sblock it. If there are other out of adventure locations that pop up, we'll deal with them then, but there are likely only going to be few, if any.
Due to the slowness of of PbP, we offer some time XP for real time in an adventure to speed things up a bit, baring players actualy participating in an adventure during that month.
Since we have judges, they will follow adventures, and pick them up if the GM leaves. Likewise, if you need more players if they go, it's fairly easy to recruit more.
In my year+ now of playing in Living Enworld, I've played in 5 adventures and ran 3. of the adventures, 1 finished with the origional judge, 1 finished by being taken over with only a short hickup, and 3 are still in progress (One of which was taken over). Of the 3 I've run, one went about 3000 posts and finished with 3 of the 6 players, and the other 2 haven't had a player drop yet (And since most of those are Enworld regulars, i'm less worried about dropage). Basicly, with the help of the other judges, no adventure should ever be lost due to GM loss, and every adventure will be resolved in some way, even if players drop, so you can continue with your character.
Do keep in mind, as far as making evil characters, that most likely more players will be good or neutral with good intentions, so you'll need to either be willing to work with them, or find GMs willing to run an evil game. I actualy tried to run an evil game in LEW, and it failed because it was too evil for the evil people (it was't like kill children and puppies or anything, but still).