Max fan speed and inaccurate thermals after liquid metal (LM) for CPU and GPU, and new SSD

I would check your mounting pressure, verify TIM coverage, and try reseating the heatsinks again. Also, you might need more than a tiny drop of Conductonaut; certainly the photos in guide show a bit too much thermal paste but there is a happy median. Liquid metal also might need a bit of help spreading around the heatsink. If you do end up completely removing the whole heat sink assembly again, check how far the liquid metal spread around the heatsink. If it's not covering >95% of each die, add more and don't be afraid to spread it around a bit with a lint-free q-tip (one should have come with the Conductonaut). Finally, some mounts won't put enough pressure; the screws bottom out before the heatsink is fully pressing onto the die. If you are finding a gap between the die and the heatsink when fully tightened, you need to use more TIM to fill in the gap. No air. Air doesn't conduct heat. Keep adding TIM until you've covered the whole die with full mounting pressure.

You probably didn't need to conformally coat and liquid e-tape the motherboard. These measures are usually taken when you are concerned about moisture (i.e. from sub-zero cooling/liquid nitrogen) or conductive dust/shavings. It will do no harm though, so don't try to remove it now that it's on there. You might break something and it's not worth the risk.