All is wrong with your user interface. The grid size, not being able to lock items, the bug where you can't reload linked pngs, I can write all day. Do you know Inksscape? Learn from those guys and save my hours of hate.
Just exactly what are you using PowerPoint for? It's not a drawing program. It would be nice if it could handle vector graphics a lot better but I doubt too many people expect PowerPoint to have the same drawing functionality as Illustrator.