My general method as DM is to offer options, so the types of adventures the characters would be involved with would depend very much on the choices made by the players. There is a lot of wilderness in the Lakelands, so travel itself can be an adventure. The campaign information above does not take into account, either, that the live-action version of Lakelands now has a little less than six years in-game time beneath its belt. I was imagining beginning the game in Selby-by-the-Water because it is both cosmopolitan and nicely central to some interesting locations.
I use a lot of non-standard monsters, and I feel free to make up my own. I make up my own diseases (more interesting/realistic ones). I make up my own poisons and addictive substances. Lots of fun stuff. Of course, I also use what's in the Core Rules and related sourcebooks as much as I want.
Wolfheart, I am imagining that a pbp will work better if the game is character-heavy rather than combat-heavy, but, again, this will depend largely on character choices.
Krug, while you could not be a dwarf psion in this setting (for Cosmological reasons Yet to Be Revealed) you could be a goblin psion. In the Lakelands, goblins are far more crafty and folkloric than they are usually portrayed. In the live game, we have had an Orc PC, so the idea of using a monster race is not completely undoable. Naturally, you would face some prejudice.
Toric, nice to hear from you.
Sado, you are correct in your assumption. Elves and gnomes both gain Sylvan instead of elvish and gnomish. Characters who would gain Orcish instead gain the Dark Tongue.
RC