Plasma membrane is made of two layer of phospholipids. The outer layer is hydrophilic while inside the membrane is hydrophobic therefore plasma membrane is not a hydrophobic barrier -it regulates what enters and leave the cell.

Cholesterol has many hydrophobic side chains and a single hydrophilic side chain. Because it contains both hydrophilic and hydrophobic groups, it is amphipathic.
yes cholesterol Hydrophobic , choestol not soluble in water

hydrophobic

Hydrophobic means that the molecule is repelled by water. You can tell if a molecule is hydrophobic by the way the atoms are arranged.

lipid bilayer of cell membrane