Hmmmn. No idea about the liquid metal pads. Never heard of them until now.
I had to experiment with a bunch of different methods of applying the thermal paste until I got fan behavior I was willing to settle for.
I did scrape every bit of paste off of the gpu memory and core unsung an old junk credit card. It took me over an hour but it's worth it. What's probably happening is the heat sink may not be sitting perfectly flush with the core because the memory chips aren't perfectly flat with the previous paste residue still on them.
For the plastic wrap it's pretty straight forward. Put a pea sized dot down then put wrap over it and press down until it's smushed out across the entire core. Then reassemble everything.
Also, make sure you screw the board into the casing.
You don't need to put the whole case back together (I never have). But you do need to screw the board back down into the case to ensure the whole heat sink assembly is applying enough pressure to maintain good contact.
