I have the same application architecture. A number of tool windows, one of which may become a document window, centered around fixed document windows. Currently I create my document windows from C# code, though design time support would be much nicer, as it would simplify handling of internationalization resources.
In fact, it is also quite annoying that if add document windows from your C# code, that the dock panel designer breaks and you have to reload this view each time you compile your code.
I know that it is quite some time since this issue was raised, but I consider fixed document windows that are surrounded by a number of complementary tool windows a fairly common use case, so it would have been nice if Actipro could have fixed this issue.
[Modified at 11/08/2009 07:49 AM]