IRS issues + health care have been the two greatest areas of stress when running my own business. I was a bit naive about both the first time around, I'm not sure I'll do it a second time.
Same here. Incredibly stressful. The only positive side is that after screwing taxes up for a few years and even being audited, the IRS has treated me with the utmost respect. They have waived penalties and interest and given me ridiculously forgiving extensions. A little humility mixed with a touch of patronization can go along way.