Believe it or not my late 2014 Mac Mini paste was the worst. I was astounded that the paste was clumpy and mostly dried out before it was even a year old.
I also like the written guides from ifixit.
But as a matter of fact, any 2014 mac is under warranty, which by taking the machine apart you have probably voided. Still seems to me Apple should be doing the repair for free for those who do not want to do it themselves.
I wonder if Apple has "hidden" warranties.