PEX Pipes running along Ceiling on Inside Wall
As long as it's oxygen-barrier PEX (red often is) then it should be just fine for baseboard heating. The reddish hue on your ceiling is odd, but I have a hunch it's just light reflecting off of the red pipe. 

Not putting it inside the walls is being a bit cheap, but, then again, there's some argument for making pipes easily accessible too. If you want to cover them, one option may be to get some crown moulding to put over it. 

As for insulation, there's no need for that as long as the pipe is on the conditioned side of the wall (as yours is).