By all means feel free to do this, but if you stop updating Chrome (and therefore whatever version of Flash you have) then you will be running an exploitable browser at some point in the near future. And by exploitable I mean you will at some point visit a page with some ads and one of those ads will contain malware that will exploit a bug that will be found in your version of Flash and will do something unpleasant to your PC.
I would strongly advise you to never disable software updates to make your life a bit easier, because there's a very high probability that you will get burned eventually. And Flash in a browser is the biggest hole in your defences, even when it's fully patched!