Thank you everyone for the tips so far.
In the meanwhile we already know that we will go the last week of May & the first week of June, or the first two weeks of June as some parks are not open yet on weekdays the third week of May.
Squeeze in Indiana Beach is tempting I must say, after having seen the Lost Coaster pics and footage of the Midwest trip. Will check this.
Also SF KK is interesting and not too far from HW. Will have to see how late we arrive on Saturday and perhaps we can squeeze in a day 0 park visit.
Swapping Knoebels and Hershey seems a very valueable tip : so Hershey will be packed on Saturday but not on Sunday ?
As we will take a Maxpass, we will include GL but considering your advice, we might visit CP the third day in the morning and only visit GL in the afternoon.
Driving into NY is not really tempting I must say. We don't really care that we will not get the additional 10 credits over there.
SF GA & Michigan's Adventure are 2 parks I didn't consider yet. Have to look whether flying to one of the 2 airports you mentioned would be an option for us. Also a visit Waldameer must be checked.
Now, in stead of going to SFNE and LC, we probably will do the following : after SFGA we drive to the south to SF America. Then we can also visit PKD and end with BGE which imo sounds more interesting than Lake Compounce as a last park of the trip. No offense to LC or their fans .
Is there a big difference btwn SROS at SFNE and SFA ? We don't want to miss the experience of riding the #1 coaster in the world of course.