One strategy we use is to create included files for common navigation elements as .inc, .txt or .htm extensions so that the include statements in ASP and PHP will both play nice.  You can see that the category navigation in http://www.ahamodernliving.com/" rel="nofollow - http://www.ahamodernliving.com/blog" rel="nofollow - www.ahamodernliving.com /blog is consistent between the store and the blog.  We have a single file which is maintained manually and works in both applications.

 

The unfortunate compromise is that session variables cannot pass between ASP and PHP, so elements such as logged in status and cart totals cannot be read and used correctly in the blog.  There may be around that but we have not pursued such an effort thus far.

 

But beyond that, as you can see, we're using WP very successfully on those and many other sites.

 

I'm not so sure that what you are seeking can't be accomplished by a competent developer, budget and schedule allowing...

 

Also, you state that you need greater flexibility with the home page.  Without knowing what your percieved home page would look like, we do all sorts of stuff with or without PC's home.asp file, but always user-maintainable.  We have never found it necessary to use a blog to create a flexible home page that is easy to manage.