When the learner hovers over a marker, it shows its hover state, which is built in to show the title. Then when they click on it, it expands to show its contents. I applaud your thought to give the markers a visited state, so learners can tell which ones they have seen.
But why do they need 10 points? You can't see the contents (and the visited state doesn't show) until the marker is clicked. If there is some requirement to visit them twice, I couldn't find it in the instructions. So I'm recommending you go for five.
The real problem is that you've fallen for the programmers hoax (that someday they will correct in SL) that "state of " is an action. It isn't, it is a condition, and only works in the "If" portion of triggers. Since the learner has to click the marker to read it, you can simply change the triggers to add to the count when the user clicks.