I should say that un-graceful shutdowns can corrupt the filesystem and should be avoided. I'd connect to the laptop from a different machine and issue a proper 'halt' or 'showdown now' to make it graceful. Speaking of connecting to it, can you connect and make sure you check all logs to see if any process has given any faults? In my experience, laptops have hardware that is peculiar (by trying to be "smart") and drivers may well fail in strange ways. Try "ALT+F1" (F1-F4 or so) to see if you can get a console before giving up on the keyboard. You may have to configure SSHD properly in order to connect form the outside (not sure what Mint has as a default config). Disable the screensaver entirely and see how it behaves. Does it go into some hibernation mode and when you wake it up it is upset or is it just happening when you go to screensaver mode? The best thing about BSD is that it is distributed fro ma single source as the FreeBSD that we all (maybe) know. The worst thing about BSD is that it is not as popular as Linux, but Apple is making it a lot easier for BSDers right now. I used to run NetBSD in the 90s. I would say stick to Linux if you are not a real Unix poweruser.