SetDynaLoadData("l2r1.p3d;l2z1.p3d;l2r4.p3d;"); UsePedGroup(5);
I think the problem is right here. You're loading Level 2 map data while using PedGroup 5.
PedGroup 5 is the group used in the trailer park area of Level 1. I've experienced crashes (while working on SHAR PLUS) from the game using a PedGroup that isn't the correct one for the level region(s) that are being loaded, so I think this is the most-likely culprit of the crash.
What you should do is change the PedGroup to the one corresponding to the map region where you start the mission:
l2r1.p3d (the construction site area) --> UsePedGroup(9);
l2z1.p3d (the town center) --> UsePedGroup(8);
l2r4.p3d (the Stadium area) --> UsePedGroup(14);
That should (hopefully) fix the crashing.
P.S. -- Yes, vehicle locators should be Type 3, not Type 0. (Type 0 is mainly for "goto" triggers.)