They are not the same.
A pedestrian is a pedestrian. At a four way stop, the rules are they have the right of way. They don't have to wait their turn, so to speak. This is pretty basic stuff here.
A bicycle is defined as a vehicle. You would treat them like any other vehicle on the road. In a perfect world, they'd stop at the stop sign and you'd all proceed accordingly.
Someone on inline skates/rollerblades would probably fall under the definition of a vehicle. You would treat them like any other vehicle.
If you're talking about any of these three using the sidewalk, just use some common sense and treat everyone as a pedestrian.