Iv'e got a 92 with a few minor (1-3inch) rust spots on the body. The frame is overall rust free and very strong. Would my best option be to simply use a grinder to get rid of the rust and then use bondo to patch up and seal the holes?

 

you never use bondo to fill in rust holes. cut the rust out and weld in new metal. if you use bondo it's just going to rust again.