From what I know, you can edit in GE. Google maps is more of a viewer with some simple location adding.
.KMZ file is the type of file GE saves it's information in.
Basically what I did
-Take your Google Map
-Click on view in Google Earth, upper right corner
-In GE organize the locations on the left hand side toolbar
-Then when finished organizing, right click on the folder in the tree, Mexico Hotels, or whatever you've compiled everything under.
-Click Save As
-This gives the .KMZ file
Also, to edit icons, from the left hand list, right click on a folder or individual, then click properties, you should be able to change an icon or the size and text around it.
To share this in GE is a little beyond me. But for our community to see it I think it has to set on a server or something like that.
I'm no expert on this stuff, so if I'm way in left field on this and someone can reel me in, please do.