Your questions assumes that Force essence controls atoms and molecules when such knowledge is
not Aelyrian
Force controls
force essence so that's what Sorcerers manipulate. It's not atoms, but at higher proficiencies you can probably assert control over a given environment to literally slow down the particles of the air to cool or heat things, or super charge things to create lightning.
What you are proposing is not impossible, given the right wording and the right moderator
As per gravity, you can just use Force to pull your target down
Stopping a target is just using force to stop them, like making an invisible wall around their figure.