Paint.NET :: How To Disable Automatic Features

You basically have to click "Expand canvas" every single time you paste a screenshot larger than the canvas. Sure, open a canvas that size, etc etc, but I'm looking for a permanent solution which would allow you to use the "Expand" choice AUTOMATICALLY, by default, without a popup. On that note, here's another annoying thing. Whenever I open images, crop out something, open a new one, paste it there, save it, etc, I usually have tons of unsaved images which I no longer need. I just want to exit the whole thing altogether without any save popups, etc. Like you would do in MSPaint. Open a canvas, paste in something, save it or don't, exit, the program closes nice and fine. My problem is:

This. I don't want to save every single image separately, because I no longer need them. Neither do I want to manually click each and every single one and tell it not to save, nor do I want to click "Don't Save" every time I exit. This may seem like pointless bitching, but trust me, it really gets on your nerves when you're using the program literally hundreds of times per day.

So, is there any way to disable these popups and define an "automatic" feature, to simply close and enlarge under any circumstances?