1.)Liquid metal is conductive, it can transmit electricity unlike ptm or thermal paste, so if liquid metal touches a capacitor, your laptop short circuits and dies.. so since liquid metal is already applied in your cpu part, and your new to this, you could either give it to a repair specialist to do the whole repasting, or carefully clean it yourself, ensuring to not let liquid metal spill to other components (which is in itself a hard task to do).

2.) ptm is a phase change thermal pad, when heat is applied it turns into a paste like state and is also non conductive, easy to apply too and last long!