Hi Willsama!
Thank you for letting us know! We're sorry for the inconvenience. We're going to try and deal with the popup issue today if at all possible.
Also, pressing "M" in combat will currently show your real frame rate. The game is presently capped at 60 fps, but the hotkey will display the maximum FPS it could be running at. Unfortunately we can't uncap the FPS for the foreseeable future, but we find the game is pretty smooth at 60 FPS.
With regard to externalising sprites and / or modding, we don't have the final word on that yet, but it is an idea we're interested in. We'll keep looking into it, and see what we can do!