is it safe to apply an update to the system from a disc ?
the game is summer sports ( pal ) and so is the consloe region....
That depends on the situation. If you have a modchip you can safely install the updates. Won't hurt anything. Now, if you run homebrew an update may or may not cause problems. I generally avoid updating because I like my Wii the way it is and I would rather Nintendo not mess with it.
More information will yield a more detailed answer.