What should I do to protect my online advice column?
Just as there are disclaimers throughout this column, it's hard to give specific advice without knowing the "whole story"--something you definitely do not get from an online question.
Your disclaimers should indicate that you're providing general information or guidance, but can't address the specific situation in detail. It's amazing the kind of trouble that people can get themselves into, and the last thing you need is to get embroiled in a lawsuit because one of your readers claimed they relied on your advice to their detriment.
Speak to an attorney to draft the disclaimers and to an insurance professional to see if your business insurance covers your online activities in the event you may be sued.