Well not sure if you NEED it but it is very handy to have for that quick tech answer and sometimes even to know that others have the sam

problems you do sometimes that is a comfort...

so if I as a question, say about my mac, does Plurk allow people to get a heads up when certain keywords are "plurked"

or only people following me can help?

Only followers will see your plurks. Add info to your profile and you might get more followers.