Go ahead and book. I've booked for other family members, some with different last names and have never had an issue.
The threads you have read about account closing are nothing more than drama from folks doing shady things. They share a similar theme - they start with only part of the story and often explicitly saying that there is no reason they have to close the account. Then, as questions are asked and answered, it becomes increasingly clear that the situations involved breaking T&Cs of the program and that there is indeed evidence of this.
If his is really "family" that happens to have bought "advice" or your promise to provide them with tickets on eBay, Craig's list, etc., then yes, you should definitely worry about having your account closed. If you are booking for actual family and friends and not selling the tickets to them, forget about those threads.
Last edited by WineCountryUA; Dec 3, 2015 at 11:15 am
Reason: Discuss the issues, not the posters