Do you know any alternative to NDepend for architects?

Nitriq is a free static code analysis tool for .net. They don't have graphs, but they do have a treemap and instead of having to learn CQL, you use LINQ to do all of your querying. You can find it at www.nitriq.com

Don't think that you are going to find anything as good as nDepend.

But a lot of what you want to do is available within Visual Studio Team Edition

• Visual studio has standard code metrics, we use maintainability index and require that all code under maintainabily index x be checked.
• For comment coverage, we set that xml doc should be generated and that warnings = errors. That way if you are missing a comment you get a compile error.
• Visual Studio also gives you code coverage for your tests

Reflector has a dependency graph addin which is available here:

http://reflectoraddins.codeplex.com/Wiki/View.aspx?title=Graph