Hi Kathryn,
Your services list seems pretty good to me. A task I recently did to define the services I wanted to offer was to simply look over my employment resume. I took a look at my resume and recalled the tasks not only I enjoyed doing, but knew I was very good at too. This helped me in deciding the tasks I truly enjoyed and helped me leave off the tasks, I know I could do, but did not want to do in the long run. This may help you in defining your services. Having a particular niche (in your case real estate lending and physician credentialing) is great, focus on those areas, as those are your greatest assets!
As far as wanting to learn new skills, like web design. It is never ever to take to take a course on something you have always wanted to learn. After all, you may come to find that there is a skill you are exceptionally good at and in the long run, you can add that to your list of services. Good Luck!