My macbook did some strange things this morning. I upgraded to Sierra the other day and it been running great. But this morning got to work and booted up. The apple logo with loading bar took ages, bit odd (8GB RAM and SSD) the was unable to move mouse or input password, after a moment it said no keyboard connected. So held power button and then turned on again..... Same, so one more try... Faster boot and keyboard and mouse works. Opened an excel sheet, would not load fully only the tool bars at top. Beachball and Command+Q not work, locked up the machine. Held power for 2-3 seconds and selected shut down. Restarted and seems ok at min. Should I be worried? Is there a keyboard combo like in windows (Windows+ALT+Del) for mac to see what running and disable selected processes?