I tried raising map to 20$ and then removing all guests, starting over, it made about no diffrence at all.
What i noticed tho is that the north entrance of the park seem to be a pain for the OpenRCT AI (the south entrance is exit only, no guests enter there), because most of the guests in park seem to have stuck there.
So I remade the entrance a bit and after that i managed to get around 1800 guests in park, instead of like 800, while in vanilla i got around 3600 guests.
http://imgur.com/a/oKudy
I also added another path around where i show in first post where they get stuck, suddenly, not stuck anymore (illustrated in paint, forgot to screenshot):
http://imgur.com/67PLiHr
So all in all, OpenRCT AI seem to have a really hard time with the park layout, while Vanilla seems not to, and maps doesent seem to change that alot.