There is no problem with system optimization - OpenGApps create a lot of CPU load during the setup phase and this dialog should only warn the user about it. If you don't like it, you shouldn't be installing OpenGApps and will be able to disable it starting with 0.5.17. This topic is discussed in
#349
Now, back to the main topic. As I have said, we are not providing support for OpenGApps - there is a reason we don't include them in our platform by default. It seems to me that you are creating your own problems by installing OpenGApps even though you don't need them. If you detect a problem with a certain app, let us know and we will check it. If your system is crashing after our update, please provide us more details about what exactly you did and we will also look into it.