Oh, nice I know exactly what you're talking about!
Pretty much I have an algorithm that keeps the blocks locked to a grid, when you go into negative space things start to go crazy and stack up on each other like you said. A fix is on the way don't worry. I do congratulate you for really pushing my game! It's really nice to have people like you who really go outside the boundaries of what most people test. Thanks for taking time to explain to me the problem in detail as well.
As for the arrow keys no problemo, I'll add that in as soon as I can. I'm working on a way to make the maps more navigable too. I think I may have said this before, but I'll let you guys know when I'm about to push a big update.
Thanks for getting back to me and giving me feedback!