0 degrees is right (ie going left to right across the screen)
put another way if your player is in the middle of a standard clock face 0 degrees is 3 o'clock, 90degrees is 6 o'clock, 180 degress 9 o.clock and 270 degrees is 12 o'clock.
mirrored flips your graphic left to right.
so in my example 4 (which you still do not appear to have downloaded ?) I say is the angle the "axe" is travelling between 90 and 270 degrees (ie going left) then flip the graphic left to right and start it rotating anticlockwise.
you only pin once - then the pinned sprite will move with what ever it is pinned to. Normally this is done when you create the sprites - if the graphics are already on the screen at the start of the game then use on start of layout.
I am learning C2 by picking out small parts of games and working out how to do them - How to move a player to follow the mouse ? How to make the player fire when he is in a certain area only ? how to change the graphics from facing left when my player is moving right ? Just small parts that could be used to make up a whole game. Read though the beginners tutorials (Ashleys especially) and try to understand why they work - please don't just load in the capx or "type in the code" but read the blurb and most of it will be explained.
You will not understand everything at once - I learn something new, or at least reinforce some understanding, nearly every day and that is after a year of using C2 several times a week.
Try to avoid every tick for anything unless it is absolutely needed to be done 60 times a second.
Maths is important.
Not looked at your video link yet.
Good luck.