Not as far as I'm aware of, though in some countries the authorities have some oversight of names, so you might be stopped from naming your child Pepsi Microsoft or other silly things.
More to the point, there are laws governing what names you can trade under. For example in the UK I think (this isn't my field, info could be wrong/out of date) sole traders and partnerships can legally trade under a personal name - so if your name was McDonald you could run a restaurant under your real name, but you'd probably have to be careful to always carefully list it as J. McDonald (London) or similar to avoid infringing McDonald's trademarks.
Sure, but I bet you'd be pissed if N. J. Harman, LTD demanded that your change your name to avoid confusion, and could enforce their demands.