After many weeks of stability, I enabled the setting to idle tabs, and set the threshold to 12. When I went to close the settings tab, the browser crashed and nothing would cause it to open again. Even a second profile would not open, which I don't yet understand.
So I renamed the whole slimjet folder under .config in .deb linux x64, and it started right up. I then synced my old settings back using google chrome sync.
Then after a while I went and reenabled the idle tabs settings again, and the browser again crashed.
I went through the restoration process again. This time I left the idle tabs setting disabled. I've been up for half an hour now with no problem.