A:AnswerYes, you can upgrade both if you have experience working on laptops. See chapter 5 of this guide.
http://h10032.www1.hp.com/ctg/Manual/c06446633
A:AnswerThe only way to upgrade a gpu is with an exp gdc card dock which works for laptops. There are vidoes on youtube such as the this one which help doing this; https://youtu.be/aM3D3cZmqn0
A:AnswerThis is a subjective question. I have one of these and it runs pretty cool and quiet.
Here's what I see in the product brochure regarding thermal mgt.:
-Enhanced thermal solution maximizes airflow to optimize overall performance and stability.
-Advanced thermal management: Optimized thermal design and IR sensor keeps your laptop cool to touch, without affecting acoustics.