Actually I may have expressed this wrong. Not sure you actually have to anchor it (don't know how to do it myself) but do your rotations, waves etc around the 'origin' of the flame. You might even use a temporary layer with a big dot on the origin and make it semi transparent so you can move the fire, strethc it do whatever and use the layer with the dot to line up the base in each frame then delete it when finished.
Here's a quick example ...
I use the blue dot and arrows on a templ layer to help me draw the flames and keep them in a certain range so they don't jump too much from frame to frame.
Looks like you can do it all now, programming, models and textures ...
