Installing new PSU - 2017

Friends, I am planning to replace my PSU with a newer one: Corsair RMx 650.

My questions are:

- Does this PSU fit?

- Is it gonna dance around?

- This PSU has got fan on the large side, whereas Alien PSU doesn't. How do I make sure it can breath?

- What if I removed the Alien casing's PSU cover? The metal box-like PSU enclosure.

- Finally, do I need extra long cables to reach 2X4 pins CPU power port? 

Thank you so much, fellow Alien commanders.

Update: Aurora R4.