Is it normal for the outside of a refrigerator compressor to be fairly hot?

yes

It is a COMPRESSOR,

You should be more around the 150 mark. "Feels like" actually you would need to take a temp reading with a thermal gun. If the outside unit has never been cleaned. This will drive up the temp on the compressor as it has to work harder, shortens the life of the equipment and causes excess usage of electricity

Pull the disconnect on the out side of the house (the box mounted) then take a garden hose on a med spay setting start at the bottom and work your way up first. Then rise off working from top to bottom. This should help out the unit allot. Airflow is critical for proper operation. .

Yes. The heat is caused by the piston in the compressor moving very rapidly, and causing friction on the casing.

They can get pretty hot. Even the ones with fans get hot enough that you can't hold your hand on them.

yes. Within the temp you describe.

yes