What are the tax implications for getting a federal tax-id for an LLC?

The bottom line is at the end of the day, the govt has a paper trail to track any income that is received by that llc. So at tax time, I would be very wary on claiming deductions, like writing off your apartment as rent for your business, that is an irs red flag that many people think will slip thru the cracks, I dealt with this company http://101taxstrategies.com and they helped me out with multiple llc's that I had and they warned me about writing off my rent and claiming furniture and writing off mileage it was an eye opener