Maybe I should do without Java and Flash then, even if it means the game videos on GOG.com store page won't work anymore. Fortunately I don't play Minecraft either.
I rather do without cool (but to me mostly useless) stuff, than compromise the security. I am not fully sure what else I will be missing then without Flash. Some browser games I presume? Oh well, I can definitely do without.
What I find interesting though that apparently e.g. Chrome is safe for Flash content, as it doesn't let it out of a sandbox. Is there any drawback to the end-user for this? If not, then this is how Flash should have been run from the very beginning.
First off, Chrome's sandboxed flash player isn't safe. It's safer, but far from safe. It just adds another layer that a hacker must exploit to get access to your system. That being said, it is better than having flash installed directly on your system, but don't be fooled into thinking you're completely safe. Also, with Chrome embedding flash directly, you can't uninstall flash from it, so there's that weakness.
It's probably not a big deal to uninstall flash altogether. It's a dying platform. Like I said, it's little more than an ad/video player at this point. Everyone is moving away (if they haven't already) with HTML5.
Java is generally pretty safe as long as you keep it updated. It's no more dangerous than Windows :). I think uninstalling Java is a bit overkill. It isn't really used by browsers much anymore, but there's plenty of software that runs in java (besides minecraft). It's probably the most popular programming language. If not, it's definitely in the top 3 (along with c/c++). But if you truly don't need java at all, then uninstall it. It's just having another door whereby someone can get access.
It's easy to go overboard with security. There is a joke among security professionals that the only safe computer is an unplugged computer (power and network). If you want to be 100% secure, you have a computer that doesn't store anything on the hard disc and is never turned on. :)