Keyboard and Mouse start behaving oddly. I've had to restart my Mac to fix this I imagine I'm hitting some serious of hotkeys but on rare occasions, my Mac will start handling keyboard AND mouse clicks in an odd way.

This just happened and, all of a sudden, here are some of the oddities that were happening.


Whether caps lock was on or off (as indicated on my keyboard by the light), ALL TEXT WAS IN CAPS.
In parallels, if I clicked on some text and moved my mouse, the text would highlight as I moved my mouse, as if I were holding down the mouse button.  I wasn't.
In Chrome (in macOS, not my parallels OS) clicking on a link would open a new tab.


There were some other odd behaviors but I didn't catch them all.  I was able to restart the machine from the macOS menu and, thankfully, this turned off whatever mode was turned on.

So, any idea what happened and how to cancel next time?  I have a hunch that this is an accessibility feature, but I have no idea what that would be much less how to turn it off.

(Just in case these details are required, I have a 2017 MBP, and I'm on the most up-to-date version of macOS High Sierra.)
The symptoms you are describing point to a stuck key which is plaguing the new 2016 through 2018 MacBooks and MacBook Pros with the new keyboard.  My guess is that one of the Shift keys may be (becoming) stuck.


Text in all caps
Text being selected as you move your mouse
New Tab/Windows opening when you click a link


Try using an external keyboard - this will confirm if the problem is the built in keyboard or not.  If the problem goes away, the keyboard needs to be replaced. 

Update (from comments below):  Since you're using an external keyboard, it's entirely possible that that keyboard is having issues.  Try using KeyCodes (free app) to see what keys are being pressed.  If a key is stuck, it will show up in this event viewer.