I use adwlauncher ex and it does not have as much space between the icons as go launcher. Plus its got a few more cool effects and customizations. I just put a shortcut to the Amazon launcher on the dock so I can launch it whenever I want.
There is no way of viewing your books from Go Launcher currently even with rooting. If you have a book currently open then the Kindle App will open it from Go Launcher, but once you close it it will not open back up. You best option (which is what I did) is to switch out the Phone shortcut for the Kindle Launcher so that way you can leave Go Launcher as Default and when you want to read a book, hit the Kindle Launcher shortcut. It is a small extra step, but not much that it will bug you.
Go Launcher's icons and spacing is totally custimizable. You can set it any way you want. I reccomend the App "Launcher" in the dock to get back to the standard kindle homepage for easy access to amazon content.