I love this, there's clearly a lot of fun with this PoS (affectionate) robot, and I think there's just a lot of cool things with this story. It is a relatively simple story propped up by a really engaging premise.
There are valid arguments for a number of good endings, depending on personal beliefs. I also love how much variation can be found in ending 4. This story has a wonderful amount of substance, and it gets me excited to see any future endeavors or possible continuation if the creator wants to go that direction.