Ever since the park moved their opening to mid-May, weekdays before Memorial Day are just as busy as during the summer because of all the school groups. After Memorial Day weekdays slow down a bit until schools let out in the second week of June. That little two week gap is one of the best times to go to the park.
However, I assume you're going to be at the park sometime the week of the 23rd? Expect about one hour lines for the big coasters. It shouldn't be too bad, but I wouldn't expect to ride every coaster. And no, the park doesn't offer Q-Bot or anything similar.
Maybe one day the park will extend their season back to early May. Everything was a walk-on, even Millennium Force and Dragster (though that may explain why they don't open that early anymore...).
Have a good time!