If I'm reading your question correctly, you *want* to buy the domain with the brand name in it. You're just asking how hard can you get slapped. Different brands react different ways. I've heard from people who keep the Apple brand & culture alive with tutorials, how-to's, reviews, etc. and they (Apple) don't bother them. But some brands are extremely protective. I good place to start would be in your Terms & Conditions if you're selling an affiliate product. That's where they determine if you're in compliance or not, and they'll keep your money if you break any of the conditions.
If you're just driving traffic to your site and monetizing in ads or adsense, you'll probably just get a cease & desist letter. If you pay the extra $9.99 for private registration, it will take them a little longer to get the cease & desist letter to you, giving you a little more time. I seriously doubt you would get sued immediately. They are going to threaten you first and send you a desist letter. Taking someone to court is expensive.
I am not a lawyer and I've never played one on TV. Take advice cautiously, or disregard it.