I guess it just comes down to what you want to do with your business. If you just want to make a couple bucks on the side and not worry to much, then I guess you'll be okay. I'm just saying there are reason's for certain things.
The EIN, whether you need it or not, is nice to have. It's free to get and you can do it online. It's nice to have when it comes to mapping your taxes and write offs. It helps the IRS when it comes to your bank accts, and things such as insurance purchased through your company.
I just cant see how you can be a company that wants to grow without some sort of legal formation from the start.
As long as you are talking with a CPA then that's all that matters, its better than anything on here.