1. can you replay the game after you win with your leveled up character, and keep all your gold/loot?

2. I read you can import your existing character into a new game? How does this work?

3. Ive read contradicting info about whether monsters respawn in levels you've already been through. Can you revisit levels and the monsters respawn?

thanks!

im pretty sure you do the replay with your old character by importing him into your new game. then you can up the difficulty and play again

cant really remember though as i havent played in a looonnng long time.

1. can you replay the game after you win with your leveled up character, and keep all your gold/loot?
Yes and no. If you beat the game on say Normal difficulty, you can start a new file on the Hard difficulty. Simply import your leveled character over your new character. On Extreme mode, this is kind of a trick. You're not supposed to be able to import your gold and loot, though you'll keep your levels and experience. There is a way to do it I found, kind of a glitch. Start an Extreme game using a file with only one player. This glitch does not work on two-player files because you need a blank Player 2 slot. Go to the pause menu and Change Players. If you only have one character, you need to press R1 to Create New and pick anyone except your character as Player 1. In the Player 2 slot, load your leveled character. The game will warn you that Extreme files will reduce your character to basics. Confirm anyway. Despite the warning, your Player 2 character should retain all of his/her stuff. For some reason, a one-player Extreme file is only Extreme in the Player 1 slot. With a two-player Extreme file, this does not work, as obviously both characters are now Extreme.

2. I read you can import your existing character into a new game? How does this work?
This is easy enough. Start a new game with any character. Press Start to bring up the Pause Menu. Scroll down to Change Players. Press Triangle to import your character. The game will warn you that this will override your current character. Just confirm the import and there you go. Like I said above, Extreme mode is a special case. You can use this import character to other effects, like import into Player 2 and drop items or sell everything Player 2 owns and delete the character to get more money. Dropping items is its own process. Technically it is cheating although it's not a cheat code. Nevertheless, it makes acquiring gems easier.

3. Ive read contradicting info about whether monsters respawn in levels you've already been through. Can you revisit levels and the monsters respawn?
Again, yes and no. The game is divided into Acts. Certain areas can be revisited, like the Wood of Sharpteeth and I think Skull Gorge. These areas do not really respawn though. I make the distinction because if I said they respawned, that implies the monsters are in the same places. But regardless, there will again be monsters. If you go through the Warehouse and kill all of the thieves, they stay dead. You can go back to the Warehouse, indeed you have to in Act II, but once you clear out the thieves, they stay cleared out.

Hope that helps.