Perhaps there’s a couple more questions you should be asking yourself (if you haven’t already):
Do I want to offer my services locally, nationally or globally?
If you were to offer your services locally (depending on you area) you might find that there isn’t enough demand for graphic design. Expanding your client base nationally or internationally means you’ll have a greater potential of clients but it might become less personal (rapport is a good thing for repeat custom). And there may be an increase in costs. Of course with video conferencing and Skype to Skype calls there isn’t too much of an issue with national/international clients but it’s still something to think about.
Who’s my target audience?; Do I want to design for a niche market or have a broader scope of work?
If you targeted a niche (and untapped) market you could well become the “go-to guy” for that client-set. If you narrow down too much however, you may be excluding potential business and not get enough clients. Of course, if you do decide to focus on a nice market it is a good idea to take occasional work from other markets to keep your portfolio varied and attract work from business not attached to your niche.