What are ALL the 119 badges that one can achieve (via Steam)

I think all the character customization options are available -- at least that's how it appeared to me as I booted up the demo for the first time last night. There's also a randomization feature if you just want to click that until you get something you like.

I also like the fact that each class can be male or female and that when sending your pet to town you can also include a limited shopping list that he'll fill (potions and identify and town portal scrolls).

I believe the demo is so large because it includes the entire game but, of course, it's locked beyond the demo part until you pay for it.

Oh, one other addition/change from the first game -- you may now "fish" with dynamite. Not very sporting, but faster -- though I think the instructions for using dynamite to fish say you won't be able to catch as many fish from a given fishing hole as you can with a fishing pole.

Experience is shared, if you're close enough to each other.

Mobs are scaled up the more players are in an area.

For these effects to happen you need to be roughly on the same screen as the other player(s)¹.

Loot is instanced for each player (i.e. you see separate loot), though of course you can trade.

See Torchlight Wiki: Multiplayer features and Torchlight Wiki: Difficulty.

¹Runic Forums: Difficulty in multiplayer?