I've decided to ask people here, wherever you live, if you guys could help me collect information and verify that the information I have collected so far is accurate. I'm only listing Volume 1 information on this post for now, but I encourage you to leave any other information you may have in the comments below and/or any useful links as well. Even if you only know a particular edition exists is useful information!
Covers, Publishers, and Release Dates for Volume 1 (so far)
Covers, Publishers, and Release Dates for Volume 2 (so far)
Covers, Publishers, and Release Dates for Volume 3 (so far)
Covers, Publishers, and Release Dates for the Artbook (so far, link coming soon)
[If I'm missing any books please tell me and I'll add them to the list]
Also, I'm acting under the assumption that the Hetalia books being released in Chinese in Taiwan and China are the same book/cover/publisher/release date with the only difference being Taiwan's birthday. If this is incorrect please let me know.