-If I set a sound playback rate to something like 0.25 it doesn't apply it first time. Then when it does apply it doesn't sound right.
The sound playback rate? There isn't a sound playback rate option in Spriter or the C2 plugin, I'm not sure what you mean.
-Looping sounds now seem to have a bit of gap between them.
In the plugin? You say now, did they not before?
-If you follow your video tutorial exactly you will find that the spriter animation wont be running on the ground, but above the sprites origin. Which I think is fine and makes more sense, but may confuse people.
The sprite origin should be set to where you want the origin from Spriter to appear(the crosshair in the canvas in Spriter)
-In your plugin tutorial you say 'Then go to the frame you'd like to import your Spriter file to'. The word frame should really be layout as I didnt understand what you meant until I watched the video.
Thank you, fixed.
-If I set a sprite position to the origin of one of the child sprites of the spriter animation in C2 it can position them at the origins position on the first frame. See comical screenshot below.
I'm not sure what you mean. The scml plugin shouldn't affect you getting the proper origin from the component sprites.
-When I restart the layout within game the sprite seems to displace from its original position.
Make sure your events to set the sprite to a position are somewhere where they will be fired upon the layout restarted. If you'd like, you can send a capx to explaining how to quickly reproduce the problem.
On a side note after working with spriter I think the following would be useful.
-Being able to reset the origin.
If you mean move the origin within Spriter, you can do this by holding the 'm' key and clicking and dragging the background. There will be a more obvious way to do this in the ui in a future version.
-Being able to individually hide and show bones including their children.
Pressing 'z' lets you select all of a bones children. The pro-version lets you right click and hide selected items.
-Being able to duplicate a branch of bones and children.
if you select items, and hold control and then click to make a change (like click to drag to a new position, click to begin an angle change or ik chain movement, etc) it will create a clone of the objects and apply to the new objects instead. Due to the complexity of all the parenting operations involved in the cloning it may take a moment or two before the clone takes effect. We will optimize this in future versions.