Not much that I can do to prevent the crashes - looks like a gradual thing: it becomes more stable, the smaller I go. But still even with 2.400 x 2.400 (48x48 squares) it crashes rather soon. We will see how it works out with the new version, but for now I plan a patchwork of standard size maps of 16x16 squares to be certain it will run good and stable later on even on medium/lower quality machines. Concerning the speed with which maps loads, this should work out well. Perhaps I will paint them much larger in Gimp and then cut them into 16x16 pieces. Placing transition points in a clever way will probably be the main trick.
I wonder if animations could run smoother on non-scrolling maps (i.e. no short stop of animation upon movement and scrolling as all squres woudl maintain their exact screen position all the time and would not have to be re-loaded)?