Mac Pro Tower, randomly hanging convinced its a hardware problem but Apple think otherwise
Yes - troubleshooting this could be easy if you take some time. Get a notepad and write down the times of the problems - day, minute, second. Over time a pattern will emerge.

Save the logs - after it crashes - run the command sudo sysdiagnose as this will package each crash and the logs for later analysis.

Pay attention to what crashes - is it a kernel panic, a freeze, an abrupt reboot. The steps to diagnose each is slightly different. We have a [chat] for getting troubleshooting help if you need a start.