Thanks for that! I've already fixed the delete issue (somehow the delete key isn't working, so I added backspace and the D key as alternatives) and the right click issue is being worked on.
The change is because I wasn't happy with the amount of features the previous version had, sticking to templates made by myself wouldn't allow users to use their creativity and create completely new sprites. In time it will hopefully have more features than the old version had, I'm able to spend a lot more time on development now.