Aurora R6 upgrades and maintenance questions

So I purchased and received my R6 a few days ago.  After the initial high of owning the coveted Alienware machine, I started to notice I don't really know much about my Aurora or how to properly maintain it.  Firstly, it is the one with water-cooling and it is my first.  From what I have read there is risk of the pump failing or the reservoir needing changing.  I'm not even sure where that is but I can see something like a radiator on the top just beneath the fins.  

I've also been noticing a slight degrade after installing a few games already.  Primarily I do use this machine to run Steam and other games but it seems after just installing half a dozen games on my system, the responsiveness and overall reliability has gone down hill.  One particular annoyance is I will get a black screen if I alt + tab to go to Windows desktop.  Seems like the game is taking reigns and won't let me see the desktop but also refusing to quit completely when I exit it.  It has happened with Days of Infamy 50% of the time which requires me to hard reset the machine.  I cannot explain it because I have not noticed it with other games, namely GTA5, Forza Horizon 3, etc.  I do play Days of Infamy about 8 out of 10 times so that could explain the high frequency at which it happens with that game.

System specs are: 7700k, M.2 256GB, 2TB (storage), 16GB Ram, RX480 8GB.

So I think that's about the essential details.  I have updated to the latest AMD drivers hoping it would solve it but I'm still getting the black screen back to desktop issue.  I'm going to throw in a bigger drive with better speed than the Seagate 2TB they included in the system and bump the memory to 32GB.  The video card is going to be a wait and see if AMD Vega will be worth it or another RX480 in Crossfire is in the cards.  

 Hope you guys can help me, I know it's not well formatted and a lot to digest so thanks in advance.