Bonus Quizzes to entice students to read their syllabus?
I'd avoid setting summative assessments (i.e. for course credit) on topics other than the subject material you expect the students to learn. Doing so might come back to bite you, even if you keep the relative contribution to a final grade as low as you are suggesting. 

Perhaps you could spend half of your first lecture rhetorically asking the sort of frequently asked questions that get your goat, while at the same time navigating your course webpage, to show where a student will find the answer to your questions. After  reading out five or so of the most commonly asked questions, the students will get the message:- the answer is likely to be on the webpage. Look for it.