There is a blog post on why it's better to have Embed Interop Types of the autodesk.inventor.interop assembly set to False
However, in this case some properties might not show up when typing your code, but they can still be accessed if you are using late binding - in case of C# you can do that by declaring a variable as dynamic
Also, GetType() will not provide the exact com type, but just a generic __ComObject
Having the Type property should be enough to identify the type of the object, but if you really need the actual COM name of it, then you can use the Microsoft.VisualBasic assembly for that.