2D Tile-based game

I am wondering if anyone can offer some help or direction on how to make a 2D tile-based game. Here are some things I'm trying to achieve using behaviors:

-Make a player walk in 4 directions using the arrow keys using tile-based movement (no diagonal movement like in games like Gauntlet or the Asteroids demo that has the rotation movement, etc.)

-Make a player shoot in each of those 4 directions depending on where he's facing using tile-based movement (no diagonal movement or rotations, just simple left,right,up,down only)

-Make an object follow a player a close distance away, but not on top of the player (like how tails follows sonic in the games) using A* pathfinding (or any kind of pathfinding) and tile-based movement (no diagonal movement or rotations)

-Make an enemy chase a player using A* pathfinding using tile-based movement (no diagonal movement or rotations)

-Make objects like power-ups appear randomly when one object is destroyed (IE: destroying a crate and a powerup appears)

I've been checking some of the demos that come with T2D, however, I am unsure of how to edit some of the behaviors in order for it to do what I'm trying to do. Thank you in advance.