Weird, huh?
Actually, no. I know that at first some of these errors and messages do not make a lot of sense, but it all comes down to the assemblies being loaded into the AppDomain of the development environment.
As you have already noticed, you cannot see the strong-typed field names of a BO until the project has been built. This is because the type editors (builders) must be able to create an instance of that object in order to reflect it (reflection). So when this object is created, it must first load it's assembly which is loaded into the current AppDomain. WHen you make a change, and this type of object is in use or there is another assembly on disk with the old name, then you can start seeing this type of behavior. This is why when you get out of Visual Studio and come back in some of these problems go away...the AppDomain is cleared and reloaded from the new assembly.
The designer loader did not provide a root component but has not indicated why.
This message can from from a number of different places, but this is an example of when you could see this. When a type editor is invoked, many times the root component is referenced which gives a reference of the BO (or root component being modified) which is called through the IDesignerHost interface. Bottom line is that when you start renaming or making some changes like this, you are going to run into some of this type of behavior....so this is actually normal 
This message can also appear when the form is being loaded through the InitializeComponent method when designing the form. There is no direct answer, but it generally comes from making a change to a class that either removes functionality or it can no longer reference the type. Hope this helps...I know that it wasn't a very straight answer