First question, are they compatible? In other words can one object using bounding box, be used with another using point?
Yes. Bounding box and per pixel, for example, treats the bounding box as a big square opaque sprite when testing collisions with per pixel sprites. Try experimenting with some sprites and settings.
[quote:2jk5xq9i]Second question, if you use point, will multiple points on one object register?
Point means the hot spot only. This can be useful if you're using really small sprites and don't need per pixel collisions. Point against bounding box checks if the hot spot is inside the bounding box, and point against per pixel checks if the hot spot is overlapping a non-transparent pixel. Image points are ignored.
[quote:2jk5xq9i]Third, why are some of my collisions, not being detected?
I have no idea. Post a .cap or some more information and maybe someone will have a chance of being able to answer this!