Okay I am going to give this one a try.
- Keep your ISO at 1600 or 3200 depending on how dark it is.
- You have a relatively fast lens at f/1.8 but depending on if you're doing group shots, you'll need higher depth of field so you might need to stop down.
- Here is my most important tip (and I am not sure if someone mentioned it already as I didn't read the whole thread): shoot RAW and underexpose your image on purpose if you have to in order to have a fast enough shutter speed to "freeze" the action. Slightly underexposed RAW files are a lot better than blurry pics. Exposure adjustments on RAW files in Lightroom is a lot better and a lot more useful than blurry images. Atleast you'll get something out of the pictures.