No, linking does not violate any rules - you can do whatever you like with your sites.
However, the message here is that the only URL that may qualify for a listing in the ODP is
www.practicematch.com
Now, part of the problem has been that there are so many of your URLS that have been submitted (like
http://www.HealthcareMatch.com/) that editors have become confused as to which is the main site, and thusly NONE have ended up being listed.
If you feel that
www.PracticeMatch.com is the main site for your business, then please resubmit that to the ONE category where you think it best fits, with a note in the description that this is the main site for your business. It won't guarantee you a listing, but it's the best possibility, as I see it.
Thanks.