Kiks73,
I've been using TerraExplorer by Skyline Software Systems (http://skylinesoft.com/skylineglobe/corporate/products/terraexplorer.aspx?) for years at my client site and TE is the closest application I've seen as a one-to-one replacement for GE. TE can handle your list of items (except for #3) out of the box and TE's API is also open. Let me know if you have any questions.