Should I exchange the SX50 for something better in low light and action mode??????

The sx50 is a superzoom extraordinaire please remember with a tiny sensor and somewhat of a slow lens. So regardless of what you learn with low light/action shots it will always probably be hit or miss unfortunately as I have found. You just cannot defeat the law of physics

I have been toying with the idea of getting an Panasonic FZ200 2.8 for low light action photos, but I have dslr for that type of stuff so I cannot justify the purchase although it would be nice to have a smaller footprint camera for those sort of situations. However l still may pull the trigger.

As far as the sx50 it is a hit or miss camera in those types of situations but it is still my fave of all the cameras I use. Your expectations are still probably a little to high, the camera is not a cure all, but pretty close and I use it as my main cam regardless of its action / low light limitations. I just don't think overall and image quality wise the sx50 can be beat compared to any other superzooms on the market right now including the FZ200.