1. The area that you focus on will depend on where buyers are buying in. Do a google search on "states with the fastest growing housing market's in 2014". Ask a local Realtor or go on Listsource or Zillow and do a search for cash sales in the largest cities in those states in the last 90 days. Write down the zip codes and market to those zip codes.
2. I have found that sellers don't really care where you are located but rather how you can perform. If you have confidence and do what you say you will do no one will question you more than likely. You can get a local phone number, a fancy website and a nice professional VA to answer your phone but if you can't preform or if you don't honor your promises what good does it do? Your reputation will soon go down the drain anyway.
3. The short answer is yes. Some states "like Tennessee for example" do have laws against wholesaling. The reason is to protect the public from fraud and real estate scammers "think the stop foreclosure guys". The best answer I will give is this, do what you say you will do and you probably won't have issues.
If you say "i will close on x date" and you don't have a buyer either call and ask for more time or cancel the contract. Remember that a buyer should never have to chase you down after a contract is signed and you should update them as to what is going on.