Answering question 1

test.gd

extends KinematicBody2D
var direction = Vector2()
 
var anim = ""
onready var animplayer = getNode("AnimationPlayer")
 
var velocity = Vector2()
 
var speed = 0
 
const TOP = Vector2(0, -1)
const DOWN = Vector2(0, 1)
const LEFT = Vector2(-1, 0)
const RIGHT = Vector2(1, 0)
 
const MAX_SPEED = 700
 
func _ready():
    set_fixed_process(true)
   
func _fixed_process(delta):
    var new_anim = "idle"
    var is_moving = Input.is_action_pressed("move_up") or Input.is_action_pressed("move_right") or Input.is_action_pressed("move_down") or Input.is_action_pressed("move_left")
   
    direction = Vector2()
    if is_moving:
        speed = MAX_SPEED
       
       
        if Input.is_action_pressed("move_up"):
            new_anim = "Backwards"
            direction += TOP
        elif Input.is_action_pressed("move_down"):
            new_anim = "Forward"
            direction += DOWN
        if Input.is_action_pressed("move_left"):
            new_anim = "Left"
            direction += LEFT
        elif Input.is_action_pressed("move_right"):
            new_anim = "Right"
            direction += RIGHT   
       
    else:
        new_anim = "idle"
        speed = 0
    
    if(new_anim != anim):
        anim = new_anim
        animplayer.play(anim)
    
    velocity = speed * direction * delta
    move(velocity)