As I client, I don't want to become a "regular" with a provider. I may repeat ever so often and have an ATF. Becoming a regular has certain baggage associated with it. First, you run the risk of actually having deep emotional feelings for the provider. This crosses the line of what a relationship with a provider should be, and it can be detrimental to one or both parties outside the hobby-- i.e. in the real world. Second, by seeing a provider on a regular basis, you are creating a pattern that could become too complacent and it some point in time you get caught up or simply caught. Third, after seeing the same provider over and over, you lose some of the spontaneity/excitement that comes with seeing someone different.
So to answer your 1st question, I don't think it is bad/wrong not to want to see a provider again. Personally, I would probably stop seeing a provider after 2 or 3 visits (within 6 months to a year) or ensure there is a large gap of time (i.e. 6 months to a year) if I were to see a certain provider on a regular basis.
To answer your second question, it completely depends on the type of provider you seek out/search for. Since you are on ECCIE, I'm going to take the leap of faith and guess that you are looking for a quality, GFE type of provider. When you see one of the gals who populate ECCIE, you won't have to worry about the answer to question #2. It will cum naturally (probably more than once

).