Starting as sole proprietor and DBA.. questions help!

Hi all. I have a few questions and any help would be incredible. Thanks in advance for anyone that takes the time to read! Basically I'm a musician and that's how I make a living - composing and playing. Everything has been done with my personal SSN. I am looking into setting up my sole proprietorship and doing a DBA, but do I have to get an EIN? (I'm in California btw). I won't have employees, but I will send 1099's for anyone that helps me out - I'll pay them as an independent contractor. Should I get one anyway? This leads me to my second question: if I DO get an EIN and file the DBA, I want to open a business checking account under that name. Many of my expenses are deductible - coffees, food, laundry (I have a studio at home as well as off-site), groceries, housekeeper, etc. So when do I choose to use the business account, etc? LAST question: since all my personal income comes from my work, how would I correctly pay myself from my business? or is that even necessary? I don't want to show income on my taxes personally when it's coming from my work - it should all be one.. any help would be great!