The first line traverses through the list of players to access a part. The second goes through the workspace.
It’s generally better to go through the Players service to access a character, because you won’t need to worry about other things in the workspace sharing the same name as a player who has joined your game.
As for question 2, game.Players.Dev_Peashie is Player object, not a Model. Using .Character takes you to the model.
For q3, always go through Players to access a player by name.
the 1st choice is more accurate. Such as, some creators have their avatar in game and this might select the in-game avatar instead of the player avatar. 2. you have to put Character because it is the name of what their character is called inside of their player. 3. as I mentioned for 1 the 1st choice would be better to use in general.
If your question has been answered, make sure to mark a solution. And I also suggest having a more informative title for any other developers who share the same question to find.