Are these things possible in Anima2D? (Additive Animations, swapping sprites etc.)

Hello,
I'm preparing for a project where I have to animate a 2D (side-scrolling) character for a game level I'm going to be making. However there are a couple of the things that I need to do that may be tricky, and I was wondering if they're plausible in Anima2D (and if so maybe some suggestions on the best way to implement it)

The things I'm wondering about are:

• Separately Animated Parts: Being able to play animations on separate parts of the model independently: basically, I want most of the character's body to play a running (or jumping etc) animation but for the arm to also be able to play a shooting animation independently (since it depends on when the player shoots, it can't sync up with the legs.) I was wondering if additive animation (I think that's the term, I heard it's a feature in Spine) is possible where you can play independent animations on different parts consecutively.
  If I need to make the arm a separate object, is there a relatively simple way to keep it anchored to the main body's shoulder?
  
  
• Swapping Sprites: I need to be able to swap out the character's hand sprite to display whichever item she's holding while staying attached to the body. Is there a way to just swap the sprite or can I layer all the sprites on and activate/deactivate them as necessary?
  
  
• Rotating Bones: I'd like to be able to rotate the bone of the gun arm in relation to the mouse position so that the player can aim. Is it possible to do this via code while still being able to play the animation? I was thinking in terms of just rotating the top bone in the arm but my lecturer said that it could possibly be done with IK constraints, idk if that's possible or which way is better. (By the way, if you're wondering why I'm not just asking my lecturer this he has experience with Spine but not Anima2D lol. I'm trying to figure out which one would be better for my project.)

I'm a noob when it comes to bone-based animation in Unity so I'm kind of clueless here how it can be manipulated and integrated etc. Any help is much appreciated!