Alienware 15 R3 Freezing/Overheating in VR Games

Hello everyone.

I have owned my Alienware 15 R3 for over a year and a half, but don't really put it to a ton of gaming.

I also own an Oculus Rift, which is compatible and my Alienware is VR ready. Lately, I have been playing a ton of VR games from Beatsaber, VRchat and Rec Room.

I've noticed lately my computer tremendously lagging and freezing for about 5-10 seconds at a time, with whatever noises and voices repeating, until it goes back into the game, fine. I also have the game graphics set to low. I've had this happen before when playing non-vr games, alike Fortnite (a major one) but instead, just freezes for good, causing me to hard exit out of the game. 

I had took it to Geeksquad and apparently the solid state drive was bad, causing it to melt I suppose. After that, I cleaned it by taking out the back cover and spraying the fans, ram etc. with air, and bought an external fan. It still froze and crash, but ran much better and played games. Now, I can play those games (I think) but moderate to heavy VR games alike Robo-recall, Rec Room, Beat-saber and VRchat always freeze like I described. 

I had been asking people and searching on line, and one result that is said, is to get the thermal paste repasted. It's never been repasted before and so I was wondering, could this be a major issue, causing the lag with VR, or could it be another? I also am getting a new battery, but my Alienware is always on the fan, on a wooden desk, plugged in. I noticed last night that my battery isn't working when I play heavy games like that, and won't charge while on VR, or gaming. I also made sure my GTX is updated and the BIOS is also.

When I first got my Alienware, it worked perfectly, until I dragged out of gaming, then noticed theses issues.

My computer also gets very hot during and after gaming.

So, my main question, i will be taking my Alienware in tomorrow to get it a new battery and repasted but I was wondering if there could be any other issues causing it? I have no major harm done to the hardware and just recently cleaned it. Please let me know, and I will included photos of recordings, specs, temperatures etc. 

After playing Rec Room. More major gaming. Had lag like I described, especially at the end.

Some temperatures a couple minutes after gaming.

Specs: